PROSPECTUS SUPPLEMENT SUMMARY

        This summary highlights certain information contained elsewhere, or incorporated by reference, in this prospectus supplement and the accompanying prospectus. As a result, this summary is not complete and does not contain all of the information that you should consider before investing in our Equity Units. You should read the following summary in conjunction with the more detailed information contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference, which are described under "Where You Can Find More Information" in this prospectus supplement. This prospectus supplement and the accompanying prospectus contain or incorporate forward-looking statements. Forward-looking statements should be read with the cautionary statements and important factors included under "Risk Factors" and "Forward-Looking Statements" in this prospectus supplement as well as the "Risk Factors" sections in our Annual Report on Form 10-K for the year ended December 31, 2014, as amended by Form 10-K/A filed on August 7, 2015, and our Quarterly Report on Form 10-Q for the quarter ended September 30, 2015.

Black Hills Corporation

        Black Hills Corporation, a South Dakota corporation, is a growth-oriented, vertically-integrated energy company headquartered in Rapid City, South Dakota. Our predecessor company, Black Hills Power and Light Company, was incorporated and began providing electric utility service in 1941. It was formed through the purchase and combination of several existing electric utilities and related assets, some of which had served customers in the Black Hills region since 1883. In 1956, we began producing, selling and marketing various forms of energy through non-regulated businesses.

        We operate principally in the United States with two major business groups: Utilities and Non-regulated Energy. Our Utilities Group is comprised of regulated Electric Utilities and regulated Gas Utilities segments, and our Non-regulated Energy Group is comprised of Power Generation, Coal Mining and Oil and Gas segments.

        Our Electric Utilities segment generates, transmits and distributes electricity to approximately 205,400 electric customers in South Dakota, Wyoming, Colorado and Montana and also distributes natural gas to approximately 44,000 gas utility customers of Cheyenne Light, Fuel and Power Company, one of our subsidiaries, in and around Cheyenne, Wyoming. Our Gas Utilities segment serves approximately 543,200 natural gas utility customers in Colorado, Nebraska, Iowa and Kansas. Our Electric Utilities own 841 megawatts (MW) of generation and 8,660 miles of electric transmission and distribution lines, and our Gas Utilities own 645 miles of intrastate gas transmission pipelines and 19,058 miles of gas distribution mains and service lines. Our Utilities Group generated net income of $86 million for the nine months ended September 30, 2015 and $101 million for the year ended December 31, 2014, and had total assets of $3.7 billion at September 30, 2015 and $3.7 billion at December 31, 2014.

        Our Power Generation segment produces electric power from our generating plants and sells the electric capacity and energy primarily to our utilities under long-term contracts. Our Coal Mining segment produces coal at our coal mine near Gillette, Wyoming, and sells the coal primarily under long-term contracts to mine-mouth electric generation facilities including our own regulated and non-regulated generating plants. Our Oil and Gas segment engages in the exploration, development and production of crude oil and natural gas, primarily in the Rocky Mountain region. Our Non-regulated Energy Group generated net income (loss) of $(96) million for the nine months ended September 30, 2015 and $30 million for the year ended December 31, 2014, and had total assets of $0.4 billion at September 30, 2015 and $0.5 billion at December 31, 2014.

Our Strategy

        Our primary strategic objective is to be a utility-centered, vertically-integrated energy company providing reliable, highly valued products and services that cost effectively meet or exceed customer expectations. Our integrated approach and focus on utility customers provides for growth opportunities in both our utility and non-regulated energy businesses. This strategy affirms our vision to be the energy partner of choice and our mission to improve life with energy.

        Black Hills intends to accomplish its strategy through targeted expansion of our electric and natural gas utilities, complemented by focused investment in risk-managed, non-regulated energy opportunities. The key elements of our business strategy are as follows:

Provide stable long-term rates for customers and increase earnings by efficiently planning, constructing and operating rate-base power generation facilities needed to serve our electric utilities.

        Our Company began as a vertically-integrated electric utility. This business model remains a core strength and strategy today, as we invest in and operate efficient power generation resources to cost effectively transmit and distribute electricity to our customers. We strive to provide power at reasonable rates to our customers and earn competitive returns for our investors.

        We believe we have a competitive power production strategy focused on low cost construction and operation of our electric generating facilities. Access to our own coal, with long-lived reserves, and third-party natural gas reserves allows us to be competitive as a power generator. Low production costs can result from a variety of factors including low fuel costs, efficiency in converting fuel into energy and low per unit operation and maintenance costs. We leverage our mine-mouth coal-fired generating capacity which strengthens our position as a low-cost producer by eliminating fuel transportation costs which often represent the largest component of the delivered cost of coal for many other utilities. In addition, we typically operate our plants with high levels of availability, compared to industry benchmarks. We aggressively manage each of these factors with the goal of achieving low production costs.

        Rate-base generation assets offer several advantages, including:

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Since the generating assets are included in utility rate base and reviewed and approved by government authorities, customer rates are more stable and predictable, and typically less expensive in the long run, than if the power was purchased from the open market through wholesale contracts that are re-priced over time;



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Regulators participate in a planning process where long-term investments are designed to match long-term energy demand;



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Investors are provided a long-term, reasonable and stable return on their investment; and



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The lower risk profile of rate based generation assets may enhance credit ratings which, in turn, can benefit both consumers and investors by lowering our cost of capital.

        Our actions to provide power at reasonable rates to our customers was exemplified in our successful request to secure the construction financing riders in Wyoming and South Dakota during the construction of our Cheyenne Prairie Generating Station. These riders reduced the total cost of the plant ultimately passed along to our customers while we constructed this plant to accommodate growth and replace plants that were closed due to environmental regulations.

Proactively integrate alternative and renewable energy into our utility energy supply while mitigating and remaining mindful of customer rate impacts.

        The energy and utility industries face uncertainty, and also potential investment opportunities, related to the potential impact of legislation and regulation intended to reduce greenhouse gas (GHG) emissions and increase the use of renewable and other alternative energy sources. To date, many states have enacted, and others are considering, some form of mandatory renewable energy standard, requiring utilities to meet certain thresholds of renewable energy generation. Some states have either enacted or are considering legislation setting GHG emissions reduction targets. Federal legislation for both renewable energy standards and GHG emission reductions is also under consideration.

        Mandates for the use of renewable energy or the reduction of GHG emissions will likely produce investment opportunities, either for our electric utilities or for our power generation business. These mandates will also most likely increase prices for electricity and/or natural gas for our utility customers. As a regulated utility we are responsible for providing safe, reasonably priced and reliable sources of energy to our customers. As a result, we employ a customer-centered strategy for complying with renewable energy standards and GHG emission regulations that balances our customers' rate concerns with environmental considerations and administrative and legislative mandates. We attempt to strike this balance by prudently and proactively incorporating renewable energy into our resource supply, while seeking to minimize the magnitude and frequency of rate increases for our utility customers.

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Colorado legislative mandates apply to our electric utility segment regarding the use of renewable energy. Therefore, we pursue cost-effective initiatives that allow us to meet our renewable energy requirements. Where permitted, we seek to construct renewable generation resources as rate base assets, which helps mitigate the long-term customer rate impact of adding renewable energy supplies. For example, the Busch Ranch Wind site, a 29 MW wind farm project, was completed in the fourth quarter of 2012, as part of our plan to meet Colorado's Renewable Energy Standard. This site has expansion potential. We submitted requests for additional renewable energy supplies in 2014 for our Colorado electric utility to help meet the renewable mandate. On October 21, 2015, we received approval from the Colorado Public Utilities Commission to build and own the $109 million, 60 MW Peak View Wind Project. Pending final approvals and permits, construction is expected to commence in the second quarter of 2016. The wind farm is expected to be placed into commercial operation by year-end 2016;



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In states such as South Dakota and Wyoming that currently have no legislative mandate on the use of renewable energy, we have proactively integrated cost-effective renewable energy into our generation supply based upon our expectation that there will be mandatory renewable energy standards in the future. For example, under two 20-year power purchase agreements, we purchase a total of 60 MW of energy from wind farms located near Cheyenne, Wyoming, for use at our Black Hills Power, Inc. and Cheyenne Light, Fuel and Power Company subsidiaries; and



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In all states in which we conduct electric utility operations, we are exploring other cost-effective potential biomass, solar and wind energy projects, particularly wind generation sites located near our utility service territories.

Provide stable long-term rates for customers and increase earnings by implementing a cost of service gas program to serve our electric and natural gas utilities.

        To further enhance our vertically-integrated utility business model, we have submitted applications with respective state utility regulators seeking approval for a cost of service gas program in Colorado, Iowa, Kansas, Nebraska, South Dakota and Wyoming. The cost of service gas program is designed to provide long-term natural gas price stability for our utility customers, while providing increased earnings opportunities for our shareholders. If approved, we will acquire natural gas reserves and

producing wells and/or drill wells. We will earn a return on the acquired and/or drilled natural gas wells/reserves while getting recovery of all our costs. We will need to obtain regulatory approval from our state utility commissions for the program. Several utilities have cost of service gas programs in place in various states, including both Wyoming and Montana.

        We have a competitive advantage related to cost of service gas in that our existing non-regulated oil and gas subsidiary could assist in drilling/acquiring and operating the gas reserves required to meet the needs of our electric and gas utilities.

Expand utility operations through selective acquisitions of electric and gas utilities consistent with our regional focus and strategic advantages.

        For more than 130 years we have provided reliable utility services, delivering quality and value to our customers. Utility operations contribute substantially to the stability of our long-term cash flows, earnings and dividend policy. Our tradition of accomplishment supports efforts to expand our utility operations into other markets, most likely in areas that permit us to take advantage of our intrinsic competitive advantages, such as baseload power generation, system reliability, superior customer service, community involvement and a relationship-based approach to regulatory matters. Utility operations also enhance other important business development opportunities, including gas transmission pipelines and storage infrastructure, which could promote other non-regulated energy operations.

        We have and will continue to pursue the purchase of not only large utility properties, but also smaller, private or municipal utility systems, which can be easily integrated into our operations. We purchased several small natural gas distribution systems in Kansas, Iowa and Wyoming in the past several years. We have a scalable platform of systems and processes, which simplifies the integration of our utility acquisitions. Merger and acquisition activity has continued in the utility industry and we expect to consider such opportunities if they advance our long-term strategy and add shareholder value.

Build and maintain strong relationships with wholesale power customers of both our utilities and non-regulated power generation business.

        We strive to build strong relationships with other utilities, municipalities and wholesale customers. We believe we will continue to be a primary provider of electricity to wholesale utility customers, who will continue to need products, such as capacity, in order to reliably serve their customers. By providing these products under long-term contracts, we help our customers meet their energy needs. We also earn more stable revenues and greater returns over the long term than we could by selling energy into more volatile spot markets. In addition, relationships that we have established with wholesale power customers have developed into other opportunities. Municipal Energy Agency of Nebraska, Montana Dakota Utilities Co., a regulated utility division of MDU Resources Group, Inc., and the City of Gillette, Wyoming were wholesale power customers that are now joint owners in two of our power plants, Wygen I and Wygen III.

Transition oil and gas business to support cost of service gas initiative while maintaining upside value optionality.

        Our strategy is to transition our oil and gas business toward supporting our cost of service gas program, while maintaining the upside value optionality of our Piceance Basin and other assets. In the current low energy commodity price environment, we can best utilize our oil and gas expertise to develop and operate the cost of service gas program on behalf of our utility businesses. Our oil and gas strategy for the last several years has been to prove up the southern Piceance Basin asset, while improving our drilling and completion operations. We have drilled 17 wells and completed 13, with production meeting or exceeding our expectations on the completed wells. Drilling and completion

costs keep trending down as we focus on efficiencies and cost reductions. We are currently assessing the Piceance wells to determine their fit for a cost of service gas program.

        Oil and gas will rationalize its asset base. In the current price environment, we have reduced future capital expenditures and staffing to improve financial performance.

Selectively grow our non-regulated power generation business in targeted regional markets by developing assets and selling most of the capacity and energy production through mid- and long-term contracts primarily to load-serving utilities.

        While much of our recent power plant development has been for our regulated utilities, we seek to expand our non-regulated power generation business by developing and operating power plants in regional markets based on prevailing supply and demand fundamentals, in a manner that complements our existing fuel assets and marketing capabilities. We seek to grow this business through the development of new power generation facilities and disciplined acquisitions primarily in the western region, where we believe our detailed knowledge of market and electric transmission fundamentals provides us a competitive advantage and, consequently, increases our ability to earn attractive returns. We prioritize small-scale facilities that serve incremental growth or provide critical back up to renewable resources and are typically easier to permit and construct than large-scale generation projects.

        Most of the energy and capacity from our non-regulated power facilities is sold under mid- and long-term contracts. When possible, we structure long-term contracts as tolling arrangements, whereby the contract counterparty assumes the fuel risk. Going forward, we will continue to focus on selling a majority of our non-regulated capacity and energy primarily to load-serving utilities under long-term agreements that have been reviewed or approved by state utility commissions. An example of this strategy is the 200 MW of combined-cycle gas-fired generation constructed by our non-regulated power generation subsidiary to serve our Black Hills Colorado Electric Utility Company, LP utility subsidiary. The plant commenced operations on January 1, 2012, under a 20-year tolling agreement.

        We have initiated a strategic review for optimizing the value of Black Hills Colorado IPP's 200 megawatt generating facility and associated 20-year power purchase agreement. This is one of the two assets owned by our power generation segment. Current market prices indicate a premium valuation might be achieved. We will consider selling a minority interest in this plant if a premium valuation could be achieved. Net proceeds would be used to reduce financing needs for the SourceGas acquisition described below.

Diligently manage the credit, price and operational risks inherent in buying and selling energy commodities.

        Over the last decade or so, Black Hills has strategically refocused itself as a utility-centered energy company. Most of our buying and selling activities are directly related to maintaining utilities operations, mainly by purchasing fuel for our power generating units and purchasing natural gas for distribution to our natural gas utility customers. Our oil and gas business has a natural long position created by its natural gas and crude oil production. We sell this production into the open market and hedge some of the price risk for future production using financial derivatives.

        All of our buying and selling activities to support operations require effective management of counterparty credit risk. We mitigate this risk by conducting business with a diverse group of creditworthy counterparties. In certain cases where creditworthiness merits security, we require prepayment, secured letters of credit or other forms of financial collateral. We establish counterparty credit limits and employ continuous credit monitoring, with regular review of compliance under our credit policy by our Executive Risk Committee. Our oil and gas and power generation operations require effective management of price and operational risks related to adverse changes in commodity

prices and the volatility and liquidity of the commodity markets. To mitigate these risks, we implemented risk management policies and procedures. Our oversight committees monitor compliance with these policies.

Maintain an investment grade credit rating and ready access to debt and equity capital markets.

        Access to capital has been and will continue to be critical to our success. We have demonstrated our ability to access the debt and equity markets, resulting in sufficient liquidity. We require access to the capital markets to fund our planned capital investments or acquire strategic assets that support prudent business growth. Our access to adequate and cost-effective financing depends upon our ability to maintain our investment-grade issuer credit rating.

Pending SourceGas Acquisition

        On July 12, 2015, Black Hills Utility Holdings, Inc., our direct wholly-owned subsidiary ("Black Hills Utility Holdings"), entered into a Purchase and Sale Agreement (the "Purchase and Sale Agreement") to acquire SourceGas Holdings LLC and its subsidiaries ("SourceGas") from investment funds managed by Alinda Capital Partners and GE Energy Financial Services, a unit of General Electric Co. (the "Transaction"), for approximately $1.89 billion. The effective purchase price is estimated to be $1.74 billion after taking into account approximately $150 million of tax benefits consisting of acquired NOLs and goodwill tax benefits resulting from the Transaction. The purchase price is subject to customary post-closing adjustments for cash, capital expenditures, indebtedness and working capital.

        SourceGas primarily operates four regulated natural gas utilities serving approximately 425,000 customers in Arkansas, Colorado, Nebraska and Wyoming and a 512 mile regulated intrastate natural gas transmission pipeline in Colorado. Following completion of the Transaction, SourceGas will be a wholly-owned subsidiary of Black Hills Utility Holdings.

        The Purchase and Sale Agreement contains various representations, warranties, and covenants with respect to SourceGas' Arkansas, Colorado, Nebraska and Wyoming utility businesses, as well as customary closing conditions. Completion of the Transaction is also subject to regulatory approvals from the Arkansas Public Service Commission, Colorado Public Utilities Commission, Nebraska Public Service Commission and Wyoming Public Service Commission. The Transaction is expected to close during the first half of 2016. The Company has guaranteed the full and complete payment and performance of Black Hills Utility Holdings.

        We expect to finance the Transaction with $260 million of proceeds from this offering of Equity Units, approximately $221 million of proceeds from our concurrent common stock offering, approximately $450 million of new long-term indebtedness and the continuation of a portion of SourceGas's debt as of the closing of the Transaction, with the remainder being funded from cash on hand (which may include proceeds of a potential sale of a portion of Black Hills Colorado IPP, LLC), draws under our revolving credit agreement or other short term financings. In the alternative, we may pay down or refinance a portion of the existing debt of SourceGas with proceeds from this offering of Equity Units, the concurrent common stock offering or any new debt we may issue or incur.

        On August 6, 2015, we entered into a Bridge Term Loan Agreement with Credit Suisse AG as the Administrative Agent and 10 additional banks, collectively, for commitments totaling $1.17 billion (the "Bridge Term Loan Agreement"). In lieu of one or more of the financing sources described above, we may draw up to $1.17 billion on this loan to fund the Transaction and related expenses. The Bridge Term Loan Agreement contains the same customary affirmative and negative covenants as are in our revolving credit agreement and term loan agreement, such as limitations on the creation of new indebtedness and on certain liens, restrictions on certain transactions, and maintaining a recourse leverage ratio not to exceed 0.75 to 1. In the event we fund under the Bridge Term Loan Agreement,

in certain circumstances, we are required to pay down those borrowings with funds received from the proceeds of equity and debt offerings and asset sales.

        After giving effect to the Transaction, pro forma net income (loss) (GAAP), pro forma net income, as adjusted (non-GAAP) and pro forma EBITDA, as adjusted (non-GAAP), for the nine months ended September 30, 2015 would have been $(26.1) million, $93.4 million and $417.2 million, respectively, and for the year ended December 31, 2014 would have been $129.7 million, $129.7 million and $522.2 million, respectively. For a reconciliation of pro forma net income, as adjusted (non-GAAP) and pro forma EBITDA, as adjusted (non-GAAP), to pro forma net income (GAAP), see "—Non-GAAP Financial Measures." We expect the Transaction to be accretive to earnings per share, as adjusted (non-GAAP) beginning in the first calendar year following closing of the Transaction, or 2017 if the Transaction closes in the first half of 2016 as currently expected.

Acquisition Rationale

        We believe the Transaction will provide us with the following significant benefits:

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Fits regulated growth strategy.  The Transaction is strategic and accretive, delivering on our commitment to earnings growth and long-term shareholder value. SourceGas fits in terms of geography, size, scope and culture. By continuing to leverage our core competencies and regional expertise, by expanding our business in Colorado, Nebraska and Wyoming and expanding our footprint into Arkansas, we expect to realize operating efficiencies and add to the scale of our regulated utility business, benefitting both customers and shareholders.



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Accretive to earnings.  We expect the Transaction will be accretive to earnings per share, as adjusted (non-GAAP) beginning in 2017 (assuming a closing in the first half of 2016) and support long-term earnings growth. Also, we expect the acquisition of SourceGas to generate cash flow to support investment in the business and shareholder returns.



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Supports dividend growth.  We recently increased our dividend for the 45^th consecutive year and we have paid dividends continuously since 1942. The acquisition of SourceGas is expected to support additional dividend growth at a sustainable payout ratio.



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Provides geographic and regulatory diversity.  The addition of SourceGas increases our business diversity and adds a progressive and highly-rated regulatory environment.

Sources and Uses

        The estimated sources and uses of the funds for the Transaction, assuming the Transaction had closed on September 30, 2015, are shown in the table below. Actual amounts will vary from estimated amounts depending on several factors, including:

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the final purchase price, which will be adjusted by the amount by which net working capital of SourceGas is greater than or less than zero at closing, capital expenditures incurred by SourceGas from March 31, 2015 through closing and indebtedness of SourceGas at closing;



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the amount of net proceeds that we receive from this offering of our Equity Units;



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the amount of net proceeds that we receive from our concurrent offering of common stock;



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the amount of net proceeds, if any, that we receive from a proposed future debt offering to finance the Transaction (which also depends on the net proceeds from this offering of Equity Units and the concurrent offering of our common stock);



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the amount of indebtedness of SourceGas that we pay down or refinance at closing; and



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changes in our debt balances and net working capital from September 30, 2015 to the closing.

        There can be no assurance that the Transaction or any of the other financing transactions will be consummated under the terms contemplated or at all. Even if the Transaction or any other financing transactions do not occur, the Equity Units sold in this offering will remain outstanding, and we will not have any obligation to offer to repurchase any or all of the Equity Units sold in this offering.

Other Information

        Our principal executive offices are located at 625 Ninth Street, Rapid City, South Dakota 57701 and our telephone number is 605-721-1700. We maintain a website at www.blackhillscorp.com where general information about us is available. We are not incorporating the contents of the website into this prospectus supplement. For additional information regarding our business, we refer you to our filings with the SEC incorporated into this prospectus supplement by reference. Please see "Where You Can Find More Information."

Concurrent Common Stock Offering

        Concurrently with this offering, we are offering, by means of a separate prospectus supplement, 5,500,000 shares of common stock (or 6,325,000 shares if the underwriters of that offering exercise in full their option to purchase additional shares of common stock). This offering of Equity Units is not contingent on the concurrent offering of common stock and the concurrent offering of common stock is not contingent upon this offering of Equity Units. See "Concurrent Common Stock Offering."

Recent Developments

        On November 17, 2015, Black Hills Utility Holdings entered into a settlement agreement with the Staff of the Colorado Public Utilities Commission and the Office of Consumer Counsel resolving the issues relating to the joint application seeking approval of the purchase of SourceGas. The agreement prohibits any change in customer base rates for at least three years for SourceGas Distribution customers in Colorado and two years for Rocky Mountain Natural Gas LLC, an intrastate pipeline. The settling parties to the agreement are conditionally prohibited from challenging the rates and revenue requirements of SourceGas in Colorado for five years after the closing of the Transaction. Black Hills Utility Holdings will not seek recovery of any acquisition premium from the acquired Colorado customers and will reduce annual SourceGas Distribution customer charges by $200,000 per year for up to five years. The settlement agreement is subject to approval by the Colorado Public Utilities Commission before its terms become effective. As part of the settlement, the parties will request that the Colorado Public Utilities Commission issue a final decision by December 31, 2015.

The Offering

        In this offering summary, "Black Hills," "we," "us," "our" and the "Company" refer only to Black Hills Corporation and any successor obligor, and not to any of its subsidiaries.

What are Equity Units?

        Equity Units may be either Corporate Units or Treasury Units, as described below. The Equity Units will initially consist of 5,200,000 Corporate Units (or 5,980,000 Corporate Units if the underwriters exercise their option to purchase additional Equity Units in full), each with a stated amount of $50. You can create Treasury Units from Corporate Units that you own as described below under "How can I create Treasury Units from Corporate Units?" You can also recreate Corporate Units from Treasury Units that you own as described below under "How can I recreate Corporate Units from Treasury Units?"

What are the components of a Corporate Unit?

        Each Corporate Unit initially consists of a contract to purchase Black Hills's common stock in the future and a 1/20, or 5%, undivided beneficial ownership interest in $1,000 principal amount of Black Hills's 2015 Series A 3.50% remarketable junior subordinated notes due 2028 (the "RSNs"). The undivided beneficial ownership interest in the RSNs corresponds to $50 principal amount of the RSNs. Initially, the RSNs will be issued in minimum denominations of $1,000 and integral multiples of $1,000. You will own the undivided beneficial ownership interest in the RSNs comprising part of each of your Corporate Units, but the RSNs will be pledged to us through the collateral agent to secure your obligation under the related purchase contract.

        Upon a successful optional remarketing (as defined under "What is an optional remarketing?"), the RSNs comprising part of the Corporate Units will be replaced by the Treasury portfolio described below under "What is the Treasury portfolio?" Once replaced, the applicable ownership interest in the Treasury portfolio will be pledged to us through the collateral agent to secure your obligation under the related purchase contract.

What is a purchase contract?

        Each purchase contract, whether part of a Corporate Unit or Treasury Unit, that is a component of an Equity Unit obligates you to purchase, and obligates us to sell, on November 1, 2018, or if such day is not a business day, the following business day (which we refer to as the "purchase contract settlement date"), for $50 in cash, a number of shares of our common stock equal to the "settlement rate." You may satisfy your obligation to purchase our common stock under the purchase contracts as described under "How can I satisfy my obligation under the purchase contracts?" below.

        The settlement rate will be calculated (subject to adjustment under the circumstances set forth in "Description of the Purchase Contracts—Anti-dilution Adjustments" and "Description of the Purchase Contracts—Early Settlement Upon a Fundamental Change") as follows:

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if the applicable market value (as defined below) of our common stock is equal to or greater than the "threshold appreciation price" of $47.2938, the settlement rate will be 1.0572 shares of our common stock (we refer to this settlement rate as the "minimum settlement rate");



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if the applicable market value of our common stock is less than the threshold appreciation price but greater than the "reference price" of $40.25, which will be the public offering price of our common stock in the concurrent common stock offering, the settlement rate will be a number of shares of our common stock equal to $50 divided by the applicable market value, rounded to the nearest ten thousandth of a share; and

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if the applicable market value of our common stock is less than or equal to the reference price, the settlement rate will be 1.2422 shares of our common stock (we refer to this settlement rate as the "maximum settlement rate").

        The threshold appreciation price is equal to $50 divided by the minimum settlement rate (such quotient rounded to the nearest $0.0001), which is $47.2938 and represents appreciation of approximately 17.5% over the reference price.

        "Applicable market value" means the average volume-weighted average price, or VWAP, of our common stock for the trading days during the 20 consecutive scheduled trading day period ending on the third scheduled trading day immediately preceding the purchase contract settlement date (the "market value averaging period"). The "VWAP" of our common stock means, for the relevant trading day, the per share VWAP on the principal exchange or quotation system on which our common stock is listed or admitted for trading as displayed under the heading Bloomberg VWAP on Bloomberg page "BKH <EQUITY> AQR" (or its equivalent successor if such page is not available) in respect of the period from the scheduled open of trading on the relevant trading day until the scheduled close of trading on the relevant trading day (or if such VWAP is unavailable, the market price of one share of our common stock on such trading day determined, using a volume-weighted average method, by a nationally recognized independent investment banking firm retained for this purpose by us). A "trading day" means, for purposes of determining a VWAP or closing price, a day (i) on which the principal exchange or quotation system on which our common stock is listed or admitted for trading is scheduled to be open for business and (ii) on which there has not occurred or does not exist a market disruption event, as defined in "Description of the Purchase Contracts—Purchase of Common Stock."

        If 20 trading days for our common stock have not occurred during the market value averaging period, all remaining trading days will be deemed to occur on the third scheduled trading day immediately prior to the purchase contract settlement date and the VWAP of our common stock for each of the remaining trading days will be the VWAP of our common stock on that third scheduled trading day or, if such day is not a trading day, the closing price, as defined in "Description of the Purchase Contracts—Purchase of Common Stock," as of such date.

        We will not issue any fractional shares of our common stock upon settlement of a purchase contract. Instead of a fractional share, you will receive an amount of cash equal to the percentage of a whole share represented by such fractional share multiplied by the closing price of our common stock on the trading day immediately preceding the purchase contract settlement date (or the trading day immediately preceding an early settlement date, in the case of early settlement). If, however, a holder surrenders for settlement at one time more than one purchase contract, then the number of shares of our common stock issuable pursuant to such purchase contracts will be computed based upon the aggregate number of purchase contracts surrendered.

Can I settle the purchase contract early?

        Prior to the purchase contract settlement date, subject to certain blackout periods (as described herein), you can settle a purchase contract by paying $50 in cash per Corporate Unit or Treasury Unit (and, under certain circumstances, accrued and unpaid contract adjustment payments payable on the next contract adjustment payment date). If you settle a purchase contract early, your pledged ownership interest in the RSNs, the applicable ownership interests in the Treasury portfolio or the Treasury securities underlying the relevant Treasury Unit will be released to you and 1.0572 shares of our common stock, subject to adjustments, will be issued to you pursuant to the purchase contract (subject to adjustment as described below under "Description of the Purchase Contracts—Anti-dilution Adjustments"), subject to the provisions described below under "What happens if there is early settlement upon a fundamental change?" with respect to early settlements upon a fundamental change. You may only elect early settlement in integral multiples of 20 Corporate Units or 20 Treasury Units;

provided that, if the Treasury portfolio has replaced the RSNs as a component of the Corporate Units as a result of a successful optional remarketing, holders of Corporate Units may settle early only in integral multiples of 16,000 Corporate Units. See "Description of the Purchase Contracts—Early Settlement."

        Your early settlement right is subject to the condition that, if required under the U.S. federal securities laws, we have a registration statement under the Securities Act of 1933, as amended (the "Securities Act"), in effect and an available prospectus covering any securities deliverable upon settlement of a purchase contract. We have agreed that, if such a registration statement is required, we will use our commercially reasonable efforts to have a registration statement in effect on the applicable early settlement date and to provide a prospectus in connection therewith, covering any securities to be delivered in respect of the purchase contracts being settled, subject to certain exceptions. In the event that you seek to exercise your early settlement right and a registration statement is required to be effective in connection with the exercise of such right but no such registration statement is then effective, your exercise of such right will be void unless and until such a registration statement is effective. For so long as there is a material business transaction or development that has not yet been publicly disclosed, we will not be required to file such registration statement or provide such a prospectus, and the early settlement right will not be available, until we have publicly disclosed such transaction or development; provided that we will use commercially reasonable efforts to make such disclosure as soon as it is commercially reasonable to do so.

What is the Treasury portfolio?

        Upon a successful optional remarketing, the RSNs will be replaced by the Treasury portfolio. The Treasury portfolio is a portfolio of U.S. Treasury securities consisting of:

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U.S. Treasury securities (or principal or interest strips thereof) that mature on or prior to the purchase contract settlement date in an aggregate amount at maturity equal to the principal amount of the RSNs underlying the undivided beneficial ownership interests in the RSNs included in the Corporate Units on the optional remarketing date; and



•

U.S. Treasury securities (or principal or interest strips thereof) that mature on or prior to the purchase contract settlement date in an aggregate amount at maturity equal to the aggregate interest payment (assuming no reset of the interest rate) that would have been paid to the holders of the Corporate Units on the purchase contract settlement date on the principal amount of the RSNs underlying the undivided beneficial ownership interests in the RSNs included in the Corporate Units on the optional remarketing date.

        If, on the optional remarketing date, U.S. Treasury securities (or principal or interest strips thereof) that are to be included in the Treasury portfolio have a yield that is less than zero, then the cash proceeds from the remarketing (and not the U.S. Treasury securities) will be substituted for the RSNs that are components of the Corporate Units and will be pledged to us through the collateral agent to secure the Corporate Unit holders' obligation to purchase our common stock under the purchase contracts. In addition, in such case, references to "Treasury security" and "U.S. Treasury securities (or principal or interest strips thereof)" in connection with the Treasury portfolio will, thereafter, be deemed to be references to such amount of cash.

What is a Treasury Unit?

        A Treasury Unit is a unit created from a Corporate Unit by substituting the pledged undivided beneficial ownership interest in the RSNs that secures a holder's obligation under the purchase contract with a sufficient amount of Treasury securities. A Treasury Unit consists of a purchase contract and a 1/20, or 5%, undivided beneficial ownership interest in a zero-coupon U.S. Treasury security with a principal amount at maturity of $1,000 that matures on October 31, 2018 (for example, CUSIP

No. 912820ZE0), which we refer to as a "Treasury security." The ownership interest in the Treasury security that is a component of a Treasury Unit will be owned by you, but will be pledged to us through the collateral agent to secure your obligation under the related purchase contract.

How can I create Treasury Units from Corporate Units?

        Each holder of Corporate Units will have the right, at any time prior to a successful remarketing and other than during a blackout period, to substitute Treasury securities which must be purchased in the open market at the expense of the Corporate Unit holder (unless otherwise owned by the holder) for the related undivided beneficial ownership interest in RSNs held by the collateral agent. The Treasury securities must have an aggregate principal amount at maturity equal to the aggregate principal amount of the RSNs underlying such holder's Corporate Units. Because Treasury securities and the RSNs are issued in minimum denominations of $1,000, holders of Corporate Units may only make these substitutions in integral multiples of 20 Corporate Units. Each of these substitutions will create Treasury Units, and the RSNs underlying the holder's Corporate Units will be released upon substitution to the holder and will be tradable separately from the Treasury Units.

How can I recreate Corporate Units from Treasury Units?

        Each holder of Treasury Units will have the right, at any time prior to a successful remarketing and other than during a blackout period, to recreate Corporate Units, by substituting for the related Treasury securities held by the collateral agent RSNs having an aggregate principal amount equal to the aggregate principal amount at maturity of the Treasury securities for which substitution is being made. Because Treasury securities and the RSNs are issued in minimum denominations of $1,000, holders of Treasury Units may make these substitutions only in integral multiples of 20 Treasury Units. Each of these substitutions will recreate Corporate Units and the applicable Treasury securities will be released to the holder and will be tradable separately from the Corporate Units.

What payments am I entitled to as a holder of Corporate Units?

        Subject to any deferral as described under "Are payments subject to deferral?" below, holders of Corporate Units will be entitled to receive:

•

quarterly cash payments consisting of their pro rata share of interest payments on the RSNs, at the rate of 3.50% per year, and



•

quarterly contract adjustment payments at the rate of 4.25% per year on the stated amount of $50 per Corporate Unit until the earliest of the occurrence of:



•

a termination event,



•

the purchase contract settlement date;



•

the fundamental change early settlement date (in the case of early settlement upon a fundamental change); or



•

the most recent contract adjustment payment date on or before any early settlement with respect to the related purchase contracts (in the case of early settlement other than upon a fundamental change).

        Our obligations with respect to the contract adjustment payments will be subordinated and junior in right of payment to our obligations under any of our Priority Indebtedness (as defined under "Description of the Remarketable Junior Subordinated Notes—Subordination").

What payments will I be entitled to if I convert my Corporate Units to Treasury Units?

        Subject to any deferral as described under "Are payments subject to deferral?" below, holders of Treasury Units will be entitled to receive quarterly contract adjustment payments from us at the rate of 4.25% per year on the stated amount of $50 per Treasury Unit. There will be no interest payments in respect of the interest in Treasury securities that is a component of the Treasury Units. To the extent that such holders of Treasury Units continue to hold the RSNs that were released to them when they created the Treasury Units, such holders will continue to receive the scheduled interest payments on their separate RSNs, subject to our right to defer such payments and subject to any modifications made thereto pursuant to a successful remarketing.

Are payments subject to deferral?

        We have the right to defer all or part of the contract adjustment payments but not beyond the purchase contract settlement date (or, with respect to an early settlement upon a fundamental change, not beyond the fundamental change early settlement date or, with respect to an early settlement other than upon a fundamental change, not beyond the contract adjustment payment date immediately preceding the early settlement date).

        Any deferred contract adjustment payments will accrue additional contract adjustment payments at the rate equal to 7.75% per annum (which is equal to the rate of total distributions on the Corporate Units), compounded on each contract adjustment payment date, to, but excluding, the contract adjustment payment date on which such deferred contract adjustment payments are paid. We refer to additional contract adjustment payments that accrue on deferred contract adjustment payments as "compounded contract adjustment payments." We may pay any deferred contract adjustment payments (including compounded contract adjustment payments thereon) on any scheduled contract adjustment payment date.

        If we exercise our option to defer the payment of contract adjustment payments, then until the deferred contract adjustment payments (including compounded contract adjustment payments thereon) have been paid, we generally will not declare or pay dividends or distributions on, or redeem, purchase or acquire or make a liquidation payment with respect to, any shares of our capital stock, or make any payment of principal of, or interest or premium, if any, on, or repay, repurchase or redeem any of our debt securities that upon a liquidation ranks on parity with, or junior to, the contract adjustment payments, or make any guarantee payments under any guarantee by us of securities of any of our subsidiaries if our guarantee ranks on parity with, or junior to, the contract adjustment payments, in each case, subject to the exceptions set forth under "Description of the Purchase Contracts—Contract Adjustment Payments."

        In addition, prior to any successful remarketing of the RSNs, we may elect at one or more times to defer payment of interest on the RSNs for one or more consecutive interest periods; provided that no deferral period may extend beyond the purchase contract settlement date or the maturity date, as applicable. We may pay any deferred interest on any scheduled interest payment date occurring on or prior to the earlier of:

(a)

the purchase contract settlement date, in the case of a deferral period beginning prior to the purchase contract settlement date or



(b)

the maturity date, in the case of a deferral period beginning after the purchase contract settlement date.

        Deferred interest on the RSNs will bear interest at the interest rate applicable to the RSNs, compounded on each interest payment date to, but excluding, the interest payment date on which such deferred interest is paid.

        In the event there is any deferred interest outstanding, we may not elect to conduct an optional remarketing. In connection with any successful remarketing during the final remarketing period, all accrued and unpaid deferred interest (including compounded interest thereon) will be paid to the holders of the RSNs (whether or not the RSNs were remarketed in the remarketing) on the purchase contract settlement date in cash.

        In the event that we exercise our option to defer the payment of interest, then until the deferred interest payments (including compounded interest thereon) have been paid, we generally will not declare or pay dividends or distributions on, or redeem, purchase or acquire or make a liquidation payment with respect to, any shares of our capital stock, or make any payment of principal of, or interest or premium, if any, on, or repay, repurchase or redeem any of our debt securities that upon a liquidation rank on parity with, or junior to, the RSNs, or make any guarantee payments under any guarantee by us of securities of any of our subsidiaries if our guarantee ranks on parity with, or junior to, the RSNs, in each case, subject to the exceptions set forth under "Description of the Remarketable Junior Subordinated Notes—Dividend and Other Payment Stoppages During Interest Deferral and Under Certain Other Circumstances."

        In connection with any successful remarketing of the RSNs, the interest deferral provisions will cease to apply to the RSNs.

What are the payment dates for the Corporate Units and Treasury Units?

        Subject to any deferral as described under "Are payments subject to deferral?" above, the payments described above in respect of the Equity Units will be payable quarterly in arrears on February 1, May 1, August 1 and November 1 of each year (except that if any such date is not a business day, interest and contract adjustment payments will be payable on the following business day, without adjustment for such delay), commencing February 1, 2016. We will make these payments to the person in whose name the Equity Unit is registered on the close of business on the record date, subject to certain exceptions described herein. The "record date" means the 15th day of the calendar month immediately preceding the month in which the relevant payment date falls (whether or not a business day).

What is a remarketing?

        We refer to each of an "optional remarketing" and a "final remarketing" as a "remarketing." In a remarketing, the RSNs that are a part of Corporate Units (except, with respect to a final remarketing, where the holder has elected to settle the purchase contract through payment of separate cash) and any separate RSNs which were formerly part of Corporate Units but are now held by a holder as a separate security (the "separate RSNs") whose holders have elected to participate in the remarketing will be remarketed as described below under "What is an optional remarketing?" or, if no optional remarketing has occurred or is successful, in a final remarketing as described below under "What is a final remarketing?"

        Following any successful remarketing of the RSNs:

•

the interest rate on the RSNs may be reset as described below and under "When will the interest rate on the RSNs be reset and what is the reset rate?" below;



•

interest will be payable on the RSNs semi-annually on May 1 and November 1 of each year;



•

the RSNs will cease to be redeemable at our option, and the provisions described under "Description of the Remarketable Junior Subordinated Notes—Redemption at Our Option" and "—Redemption Procedures" will no longer apply to the RSNs; and

•

we will cease to have the ability to defer interest payments on the RSNs, and the provisions described under "Description of the Remarketable Junior Subordinated Notes—Option to Defer Interest Payments" will no longer apply to the RSNs.

        All such modifications will take effect only if the remarketing is successful, without the consent of holders, on the optional remarketing settlement date or the purchase contract settlement date, as the case may be, and will apply to all RSNs, whether or not included in the remarketing. All other terms of the RSNs will remain unchanged.

        In order to remarket the RSNs, the remarketing agent, in consultation with us, may reset the interest rate on the RSNs (either upward or downward) in order to produce the required price in the remarketing, as discussed under "What is an optional remarketing?" and "What is a final remarketing?"

        During the applicable blackout period relating to a remarketing:

•

you may not settle a purchase contract early;



•

you may not create Treasury Units; and



•

you may not recreate Corporate Units from Treasury Units.

        We have agreed to enter into a remarketing agreement with one or more remarketing agents, which we refer to as the remarketing agent, no later than 20 days prior to the first day of the final remarketing period or, if we elect to conduct an optional remarketing, no later than 20 days prior to the first day of the optional remarketing period. We will separately pay a fee to the remarketing agent for its services. The holders of the RSNs included in any remarketing will not be responsible for such fee.

What is an optional remarketing?

        Unless a termination event has occurred, we may elect, at our option, to remarket the RSNs over a period selected by us that begins on or after July 30, 2018 (the second business day immediately preceding the interest payment date prior to the purchase contract settlement date) and ends any time on or before October 15, 2018 (the eighth calendar day prior to the beginning of the final remarketing period). In any optional remarketing, the aggregate principal amount of the RSNs that are a part of Corporate Units and any separate RSNs whose holders have elected to participate in the optional remarketing will be remarketed. We refer to this period as the "optional remarketing period," a remarketing that occurs during the optional remarketing period as an "optional remarketing" and the date the RSNs are priced in an optional remarketing as the "optional remarketing date." If we elect to conduct an optional remarketing, the remarketing agent will use its commercially reasonable efforts to obtain a price for the RSNs that results in proceeds of at least 100% of the aggregate of the price of the Treasury portfolio described above under "What is the Treasury portfolio?", which we refer to as the "Treasury portfolio purchase price," and the separate RSNs purchase price as defined under "Description of the Remarketable Junior Subordinated Notes—Remarketing of RSNs That Are Not Included in Corporate Units." We will request that The Depository Trust Company, or DTC, which we refer to as the "depository," notify its participants holding Corporate Units, Treasury Units and separate RSNs of our election to conduct an optional remarketing no later than five business days prior to the first day of the optional remarketing period.

        We may not elect to conduct an optional remarketing if we are then deferring interest on the RSNs.

        An optional remarketing will be considered successful if the remarketing agent is able to remarket the RSNs for a price of at least 100% of the Treasury portfolio purchase price and the separate RSNs purchase price.

        Following a successful optional remarketing, on the optional remarketing settlement date (as defined below), the portion of the remarketing proceeds equal to the Treasury portfolio purchase price will, except as described in the following paragraph, be used to purchase the Treasury portfolio and the remaining proceeds attributable to the RSNs underlying the Corporate Units will be remitted to the purchase contract agent for distribution pro rata to the holders of such Corporate Units on the optional remarketing settlement date. The portion of the proceeds attributable to the separate RSNs sold in the remarketing will be remitted to the custodial agent for distribution on the optional remarketing settlement date pro rata to the holders of such separate RSNs.

        Following a successful optional remarketing, each Corporate Unit holder's applicable ownership interest in the Treasury portfolio or cash will be substituted for the holder's undivided beneficial ownership interest in the RSNs as a component of the Corporate Units, and the portion of the Treasury portfolio described in the first bullet under "What is the Treasury portfolio?" or such cash will be pledged to us through the collateral agent to secure the Corporate Unit holder's obligation under the related purchase contract. On the purchase contract settlement date, for each Corporate Unit, $50 of the proceeds from the Treasury portfolio will automatically be applied to satisfy the Corporate Unit holder's obligation to purchase common stock under the purchase contract and the proceeds from the portion of the Treasury portfolio described in the second bullet under "What is the Treasury portfolio?", which will equal the interest payment (assuming no reset of the interest rate) that would have been paid on the RSNs that were components of the Corporate Units at the time of the remarketing, will be paid on the purchase contract settlement date to the Corporate Unit holders.

        If we elect to conduct an optional remarketing and that remarketing is successful:

•

settlement with respect to the remarketed RSNs will occur on the third business day following the optional remarketing date, unless the remarketed RSNs are priced after 4:30 p.m. New York time on the optional remarketing date, in which case settlement will occur on the fourth business day following the optional remarketing date (we refer to such settlement date as the "optional remarketing settlement date");



•

the interest rate on the RSNs will be reset by the remarketing agent in consultation with us on the optional remarketing date and will become effective on the optional remarketing settlement date;



•

the other modifications to the terms of the RSNs, as described under "What is a remarketing?" above will become effective;



•

after the optional remarketing settlement date, your Corporate Units will consist of a purchase contract and the applicable ownership interest in the Treasury portfolio or cash, as described above; and



•

you may no longer create Treasury Units or recreate Corporate Units from Treasury Units.

        If we do not elect to conduct an optional remarketing, or no optional remarketing succeeds for any reason, the RSNs will continue to be a component of the Corporate Units or will continue to be held separately and the remarketing agent will use its commercially reasonable efforts to remarket the RSNs during the final remarketing period, as described under "What is a final remarketing?" below.

        At any time and from time to time during the optional remarketing period prior to the announcement of a successful optional remarketing, we have the right to postpone any remarketing in our sole and absolute discretion.

What is a final remarketing?

        Unless a termination event or a successful optional remarketing has previously occurred, we will remarket the RSNs during the five business day period ending on, and including, October 29, 2018 (the third business day immediately preceding the purchase contract settlement date). We refer to such period as the "final remarketing period," the remarketing during this period as the "final remarketing" and the date the RSNs are priced in the final remarketing as the "final remarketing date." In the final remarketing, the aggregate principal amount of the RSNs that are a part of Corporate Units (except where the holder thereof has elected to settle the purchase contract through payment of separate cash) and any separate RSNs whose holders have elected to participate in the final remarketing will be remarketed. The remarketing agent will use its commercially reasonable efforts to obtain a price for the RSNs that results in proceeds of at least 100% of the aggregate principal amount of all the RSNs offered in the remarketing. We will request that the depository notify its participants holding Corporate Units, Treasury Units and separate RSNs of the final remarketing no later than seven days prior to the first day of the final remarketing period. We have the right to postpone the final remarketing in our sole and absolute discretion on any day prior to the last three business days of the final remarketing period.

        A remarketing during the final remarketing period will be considered successful if the remarketing agent is able to remarket the RSNs for at least 100% of the aggregate principal amount of all the RSNs offered in the remarketing.

        Upon a successful final remarketing, settlement with respect to the remarketed RSNs will occur on the purchase contract settlement date. On the final remarketing date, if applicable, the interest rate on the RSNs will be reset by the remarketing agent in consultation with us, and will become effective on the purchase contract settlement date.

        Following a successful final remarketing, the collateral agent will remit the portion of the proceeds equal to the total principal amount of the RSNs underlying the Corporate Units to us to satisfy in full the Corporate Unit holders' obligations to purchase common stock under the related purchase contracts. Any excess proceeds attributable to RSNs underlying Corporate Units that were remarketed will be remitted to the purchase contract agent for distribution pro rata to the holders of such RSNs. Proceeds from the final remarketing attributable to the separate RSNs remarketed will be remitted to the custodial agent for distribution pro rata to the holders of the separate RSNs that were remarketed.

What happens if the RSNs are not successfully remarketed?

        If, in spite of using its commercially reasonable efforts, the remarketing agent cannot remarket the RSNs during the final remarketing period at a price at least equal to 100% of the aggregate principal amount of RSNs offered in the remarketing, a condition precedent set forth in the remarketing agreement has not been fulfilled or a successful remarketing has not occurred for any other reason, in each case resulting in a "failed remarketing," holders of all RSNs will have the right to put their RSNs to us for an amount equal to the principal amount of their RSNs. A holder of Corporate Units will be deemed to have automatically exercised this put right with respect to the RSNs underlying the Corporate Units unless, prior to 4:00 p.m., New York City time, on the second business day immediately prior to the purchase contract settlement date, the holder provides written notice of an intention to settle the related purchase contracts with separate cash and on or prior to the business day immediately preceding the purchase contract settlement date delivers to the securities intermediary $50 in cash per purchase contract. This settlement with separate cash may only be effected in integral multiples of 20 Corporate Units. Unless a holder of Corporate Units has elected to settle the related purchase contracts with separate cash, and delivered the separate cash on or prior to the business day immediately preceding the purchase contract settlement date, the holder will be deemed to have elected to apply the proceeds of the put price against the holder's obligations to us under the related

purchase contracts, thereby satisfying the holder's obligations in full, and the RSNs underlying such Corporate Units will be delivered to us and cancelled.

Do I have to participate in the remarketing?

        No. You may elect not to participate in any remarketing and to retain the RSNs underlying the undivided beneficial ownership interests in RSNs comprising part of your Corporate Units by (1) creating Treasury Units at any time other than during a blackout period, (2) settling the related purchase contracts early at any time other than during a blackout period or (3) in the case of a final remarketing, notifying the purchase contract agent prior to 4:00 p.m., New York City time, on the second business day immediately prior to the first day of the final remarketing period of your intention to settle your obligation under the related purchase contracts on the purchase contract settlement date in cash, and delivering such cash payment required under the purchase contracts to the securities intermediary on or prior to 4:00 p.m., New York City time, on the business day immediately prior to the first day of the final remarketing period. You can only elect to satisfy your obligation in cash in increments of 20 Corporate Units. See "Description of the Purchase Contracts—Notice to Settle with Cash."

Which provisions will govern the RSNs following the remarketing?

        The remarketed RSNs will be governed by the indenture under which they were issued as part of the Corporate Units. However, following any successful remarketing of the RSNs, the interest rate on the RSNs will be reset, interest will be payable semi-annually and we will cease to have the ability to redeem the RSNs at our option or defer interest payments on the RSNs, all as described under "What is a remarketing?" above.

If I am holding separate RSNs, can I still participate in a remarketing of the RSNs?

        Yes. If you hold separate RSNs, you may elect to have your RSNs remarketed by the remarketing agent along with the RSNs underlying the Corporate Units as described under "Description of the Remarketable Junior Subordinated Notes—Remarketing of RSNs That Are Not Included in Corporate Units." You may also participate in any remarketing by recreating Corporate Units at any time prior to the remarketing, other than during a blackout period.

How can I satisfy my obligation under the purchase contracts?

        You may satisfy your obligation under the purchase contracts as follows:

•

on an early settlement date as described under "Can I settle the purchase contract early?" above and under "What happens if there is early settlement upon a fundamental change?" below;



•

on the purchase contract settlement date if you own Corporate Units:



•

through the automatic application of the portion of the proceeds of a successful remarketing during the final remarketing period equal to the principal amount of the RSNs underlying the Corporate Units, as described under "What is a final remarketing?" above; or



•

in the case of a successful optional remarketing, through the automatic application of the portion of the proceeds from the Treasury portfolio or cash equal to the principal amount of the RSNs if the Treasury portfolio or cash has replaced the RSNs as a component of the Corporate Units as a result of a successful optional remarketing, as described under "What is an optional remarketing?" above; or

•

through cash settlement as described under "Do I have to participate in the remarketing?" above or through exercise of the put right or cash settlement as described under "What happens if the RSNs are not successfully remarketed?" above; or



•

on the purchase contract settlement date if you own Treasury Units through the automatic application of the proceeds of the interest in Treasury securities.

        In addition, the purchase contract and pledge agreement that governs the Equity Units provides that your obligation under the purchase contract will be terminated without any further action or notice upon the occurrence of a termination event, as defined under "Description of the Purchase Contracts—Termination."

        If you settle a purchase contract early (other than pursuant to your fundamental change early settlement right), you will be entitled to receive any accrued and unpaid contract adjustment payments (including any accrued and unpaid deferred contract adjustment payments and compounded contract adjustment payments thereon) to, but excluding, the contract adjustment payment date immediately preceding the early settlement date; provided that, under certain circumstances, you will be required to pay all contract adjustment payments payable on the contract adjustment payment date next succeeding the early settlement date to us in order to exercise the early settlement right. If you settle a purchase contract early pursuant to your fundamental change early settlement right, you will be entitled to receive any accrued and unpaid contract adjustment payments (including any accrued and unpaid deferred contract adjustment payments and compounded contract adjustment payments thereon) to, but excluding, the fundamental change early settlement date, unless the date on which the fundamental change early settlement right is exercised occurs following any record date and prior to the related scheduled contract adjustment payment date, and we are not deferring the related contract adjustment payment, in which case we will instead pay accrued and unpaid contract adjustment payments to the holder of the purchase contract as of such record date.

        If the purchase contracts are terminated as a result of a termination event, you will not have any right to receive accrued and unpaid contract adjustment payments (including any deferred contract adjustment payments and compounded contract adjustment payments thereon). See "Description of the Purchase Contracts—Early Settlement" and "Description of the Purchase Contracts—Termination."

What interest payments will I receive on the RSNs or on the undivided beneficial ownership interests in the RSNs?

        Subject to any deferral as described in "Are payments subject to deferral?" above, the RSNs will bear interest at the rate of 3.50% per year from the original issuance date to the purchase contract settlement date or, if earlier, the optional remarketing settlement date, payable quarterly in arrears on February 1, May 1, August 1 and November 1 of each year, commencing February 1, 2016 (except that if any such date is not a business day, interest will be payable on the following business day, without adjustment for such delay). On and after the purchase contract settlement date or, if earlier, the optional remarketing settlement date, interest on each RSN will be payable at the relevant reset rate (as defined under "When will the interest rate on the RSNs be reset and what is the reset rate?"), or if the interest rate has not been reset, at the initial interest rate of 3.50% per year. If a remarketing is successful, interest on the RSNs thereafter will be payable semi-annually. See "What is a remarketing?" above.

When will the interest rate on the RSNs be reset and what is the reset rate?

        The interest rate on the RSNs may be reset in connection with a successful remarketing as described above under "What is an optional remarketing?" and "What is a final remarketing?" The "reset rate" will be the interest rate determined by the remarketing agent, in consultation with us, as the rate the RSNs should bear in order for the remarketing agent to remarket the RSNs on the

remarketing date for a price of at least 100% of the Treasury portfolio purchase price plus the separate RSNs purchase price, if any, in the case of an optional remarketing, or at least 100% of the aggregate principal amount of the RSNs being offered in the remarketing, in the case of a final remarketing. In any case, the reset rate may be higher or lower than the initial interest rate on the RSNs depending on the results of the remarketing and market conditions at that time. The interest rate on the RSNs will not be reset if there is not a successful remarketing and the RSNs will continue to bear interest at the initial interest rate. The reset rate will not exceed the maximum rate permitted by applicable law.

When may the RSNs be redeemed?

        We may redeem the RSNs at our option only if there has been a failed final remarketing. In that event, any RSNs that remain outstanding after the purchase contract settlement date will be redeemable on or after November 1, 2020 at our option, in whole or in part, at any time and from time to time, at a redemption price equal to the principal amount thereof plus accrued and unpaid interest, if any, to but excluding the redemption date.

What happens if there is early settlement upon a fundamental change?

        If we are involved in a transaction that constitutes a fundamental change (as defined below) prior to the 20th business day preceding the purchase contract settlement date, you will have the right, subject to certain conditions, to accelerate and settle a purchase contract early at the settlement rate determined as described under "Description of the Purchase Contracts—Early Settlement Upon a Fundamental Change," plus an additional make-whole amount of shares, or the "make-whole shares," so long as at such time, if required under the U.S. federal securities laws, there is in effect a registration statement covering any securities to be issued and delivered in connection with such fundamental change early settlement. We refer to this right as the "fundamental change early settlement right."

        A "fundamental change" means (1) a "person" or "group" within the meaning of Section 13(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), other than us or our wholly-owned subsidiaries, files a Schedule TO or any schedule, form or report under the Exchange Act disclosing that such person or group has become the direct or indirect "beneficial owner," as defined in Rule 13d-3 under the Exchange Act, of shares of our common stock representing more than 50% of the voting power of our common stock (provided that a person shall not be deemed a beneficial owner of, or to own beneficially, (x) any securities tendered pursuant to a tender or exchange offer made by or on behalf of such person or any of such person's affiliates until such tendered securities are accepted for purchase or exchange thereunder, or (y) any securities if such beneficial ownership (i) arises solely as a result of a revocable proxy delivered in response to a proxy or consent solicitation made pursuant to the applicable rules and regulations under the Exchange Act, and (ii) is not also then reportable on Schedule 13D, Schedule 13G or any successor schedule under the Exchange Act); (2) (A) we are involved in a consolidation with or merger into any other person, or any merger of another person into us, or any other similar transaction or series of related transactions (other than a merger, consolidation or similar transaction that does not result in the conversion or exchange of outstanding shares of our common stock), in each case, in which 90% or more of the outstanding shares of our common stock are exchanged for or converted into cash, securities or other property, greater than 10% of the value of which (excluding cash payments for fractional shares and cash payments made pursuant to dissenters' appraisal rights) consists of cash, securities or other property that is not (or will not be upon or immediately following the effectiveness of such consolidation, merger or other transaction) common stock listed on the NYSE, the NASDAQ Global Select Market or the NASDAQ Global Market (or any of their respective successors); or (B) the consummation of any sale, lease or other transfer in one transaction or a series of related transactions of all or substantially all of our consolidated assets to any person other than one of our subsidiaries; (3) our common stock ceases to be listed on at least one of

the NYSE, the NASDAQ Global Select Market or the NASDAQ Global Market (or any of their respective successors); or (4) our shareholders approve our liquidation, dissolution or termination.

        We will provide each of the holders of Equity Units with a notice of the completion of a fundamental change within 10 business days after the effective date of such fundamental change. The notice will specify (1) a date (subject to postponement, as described below, the "fundamental change early settlement date"), which will be at least 10 days after the date of the notice but no later than the earlier of 20 days after the date of the notice and one business day prior to the purchase contract settlement date, on which date we will deliver shares of our common stock to holders who exercise the fundamental change early settlement right, (2) the date by which holders must exercise the fundamental change early settlement right, (3) the applicable settlement rate and number of make-whole shares, (4) the amount and kind (per share of common stock) of the cash, securities and other consideration receivable upon settlement and (5) the amount of accrued and unpaid contract adjustment payments (including any deferred contract adjustment payments and compounded contract adjustment payments thereon), if any, that will be paid upon settlement to holders exercising the fundamental change early settlement right. To exercise the fundamental change early settlement right with respect to any purchase contracts, you must deliver to the purchase contract agent at the corporate trust office of the purchase contract agent or its agent, in each case, in the continental United States of America, during the period beginning on the date we deliver notice to holders that a fundamental change has occurred and ending at 4:00 p.m., New York City time, on the third business day before the fundamental change early settlement date (such period, subject to extension as described below, the "fundamental change exercise period"), payment of $50 for each purchase contract being settled in immediately available funds.

        If you exercise the fundamental change early settlement right, we will deliver to you on the fundamental change early settlement date for each purchase contract with respect to which you have elected fundamental change early settlement, a number of shares (or exchange property units, if applicable) equal to the settlement rate described above, plus the number of make-whole shares determined by reference to the table set forth under "Description of the Purchase Contracts—Early Settlement Upon a Fundamental Change." In addition, on the fundamental change early settlement date, we will pay you the amount of any accrued and unpaid contract adjustment payments (including any deferred contract adjustment payments and compounded contract adjustment payments thereon) to, but excluding, the fundamental change early settlement date, unless the date on which the fundamental change early settlement right is exercised occurs following any record date and prior to the related scheduled contract adjustment payment date, and we are not deferring the related contract adjustment payment, in which case we will instead pay all accrued and unpaid contract adjustment payments to the holder as of such record date. The RSNs or applicable ownership interests in the Treasury portfolio or Treasury securities underlying the Corporate Units or Treasury Units, as the case may be, with respect to which you are effecting a fundamental change early settlement, will be released from the pledge under the purchase contract and pledge agreement and delivered to you on the fundamental change early settlement date. If you do not elect to exercise your fundamental change early settlement right, your Corporate Units or Treasury Units will remain outstanding and be subject to normal settlement on the purchase contract settlement date.

        We have agreed that, if required under the U.S. federal securities laws, we will use our commercially reasonable efforts to (1) have in effect throughout the fundamental change exercise period a registration statement covering the common stock and other securities, if any, to be delivered in respect of the purchase contracts being settled and (2) provide a prospectus in connection therewith, in each case in a form that may be used in connection with the fundamental change early settlement, subject to certain exceptions. In the event that a holder seeks to exercise its fundamental change early settlement right and a registration statement is required to be effective in connection with the exercise of such right but no such registration statement is then effective or a blackout period is continuing, the holder's exercise of such right will be void unless and until the registration statement is effective and no

blackout period is continuing. The fundamental change exercise period will be extended by the number of days during such period on which no such registration statement is effective or a blackout period is continuing (provided that the fundamental change exercise period will not be extended beyond the fourth business day preceding the purchase contract settlement date) and the fundamental change early settlement date will be postponed to the third business day following the end of the fundamental change exercise period. If, but for the proviso contained in the immediately preceding sentence, the fundamental change early settlement date would occur on or after the purchase contract settlement date, we will deliver to any holder of purchase contracts on the purchase contract settlement date the applicable number of make-whole shares in addition to a number of shares equal to the settlement rate, determined as if the applicable market value were equal to the relevant "stock price."

        Unless the Treasury portfolio has replaced the RSNs as a component of the Corporate Units as a result of a successful optional remarketing, holders of Corporate Units may exercise the fundamental change early settlement right only in integral multiples of 20 Corporate Units. If the Treasury portfolio has replaced the RSNs as a component of Corporate Units, holders of the Corporate Units may exercise the fundamental change early settlement right only in integral multiples of 16,000 Corporate Units.

        A holder of Treasury Units may exercise the fundamental change early settlement right only in integral multiples of 20 Treasury Units.

What is the ranking of the RSNs?

        The RSNs will be subordinated to all our existing and future Priority Indebtedness. The RSNs will be structurally subordinated to existing or future preferred stock and indebtedness, guarantees and other liabilities, including trade payables, of our subsidiaries. See "Description of the Remarketable Junior Subordinated Notes—Subordination."

How will the RSNs be evidenced?

        The RSNs that form a part of the Corporate Units will be issued in fully registered form and will be registered in the name of the purchase contract agent. The RSNs that do not form a part of the Corporate Units will be evidenced by one or more global notes registered in the name of DTC's nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC.

        In a few special situations described in "Description of the Remarketable Junior Subordinated Notes—Book Entry Issuance—The Depository Trust Company," a book-entry security representing the RSNs will terminate and interests in it will be exchanged for physical certificates representing the RSNs.

What are the U.S. federal income tax consequences related to the Equity Units and RSNs?

        Although the Internal Revenue Service (the "IRS") has issued a Revenue Ruling addressing the treatment of units similar to the Equity Units, no statutory, judicial or administrative authority directly addresses all aspects of the treatment of the Equity Units or instruments similar to the Equity Units for U.S. federal income tax purposes. Accordingly, no assurance can be given that the conclusions in the Revenue Ruling apply to the Equity Units. As a result, the U.S. federal income tax consequences of the purchase, ownership and disposition of the Equity Units are not entirely clear. In addition, there can be no assurance that the IRS or a court will agree with the characterization of the RSNs as indebtedness for U.S. federal income tax purposes.

        The terms of the Equity Units are similar to the units considered in the Revenue Ruling noted above, although they vary in some respects. Based on that Revenue Ruling, although the matter is not

free from doubt, a beneficial owner of Equity Units will be treated for U.S. federal income tax purposes as separately owning the purchase contract and the undivided beneficial ownership interests in the RSNs, the Treasury portfolio or the Treasury securities constituting the Equity Unit, as applicable. By purchasing the Corporate Units, you will be deemed to have agreed to treat the Equity Units in that manner for all U.S. federal income tax purposes. In addition, you must allocate the purchase price of the Corporate Units between the RSNs and the purchase contract in proportion to their respective fair market values, which will establish your initial tax basis in the RSNs and the purchase contract. With respect to each Corporate Unit purchased in the offering, you will be deemed to have agreed to allocate $50 to the undivided beneficial ownership interest in the RSNs and $0 to the purchase contract.

        We intend to treat the RSNs as "variable rate debt instruments" that are subject to applicable U.S. Treasury regulations that apply to "reset bonds." Under this treatment, you will be required to take into account interest payments on the RSNs at the time they are paid or accrued in accordance with your regular method of accounting for tax purposes. However, there are no U.S. Treasury regulations, rulings or other authorities that address the U.S. federal income tax treatment of debt instruments that are substantially similar to the RSNs, and therefore the U.S. federal income tax treatment of the RSNs is unclear. Under possible alternative characterizations of the RSNs, you may be required to accrue interest income in amounts that exceed the stated interest on the RSNs and/or treat as ordinary income, rather than capital gain, any gain recognized on a sale, exchange, redemption or other taxable disposition of an RSN. See "Material United States Federal Income Tax Consequences—U.S. Holders—The RSNs—Possible Alternative Characterizations."

        If the Treasury portfolio has replaced the RSNs as a component of the Corporate Units as a result of a successful optional remarketing, a beneficial owner of Corporate Units generally will be required to include in gross income its allocable share of any interest payments made with respect to such owner's applicable ownership interest in the Treasury portfolio, and, if appropriate, "original issue discount" or acquisition discount (as described under "Material United States Federal Income Tax Consequences") on the applicable ownership interest in the Treasury portfolio.

        We intend to treat contract adjustment payments as taxable ordinary income to a U.S. holder (as defined under "Material United States Federal Income Tax Consequences") when received or accrued, in accordance with the U.S. holder's regular method of tax accounting. We intend to treat any contract adjustment payments paid to a non-U.S. holder (as defined under "Material United States Federal Income Tax Consequences") as payments generally subject to U.S. federal withholding tax at a 30% rate, unless an income tax treaty reduces or eliminates such tax.

        For a more comprehensive discussion of the U.S. federal income tax consequences of an investment in the Equity Units, please see "Material United States Federal Income Tax Consequences." Prospective investors in Equity Units should consult their tax advisors regarding the particular tax consequences to them of the purchase, ownership and disposition of Equity Units (including the application and effects of any state, local, or foreign and other tax laws).

Are there limitations on the purchase, holding or disposition of the Corporate Units with assets of, or on behalf of, an employee benefit plan?

        Yes. The Employee Retirement Income Security Act of 1974, as amended ("ERISA"), Section 4975 of the Internal Revenue Code of 1986, as amended (the "Code"), and similar federal, state, local and foreign laws that are substantively similar or are of similar effect ("Similar Law") impose restrictions on the purchase, holding and disposition of Corporate Units (and the securities underlying the Corporate Units) by employee benefit plans that are subject to those laws. Corporate Units (and the securities underlying the Corporate Units) may be purchased with assets of, or on behalf of, an employee benefit plan subject to the investing fiduciary's determination that the investment satisfies

ERISA's fiduciary standards and other requirements under ERISA, the Code and/or Similar Law. An investing fiduciary that proposes to cause an employee benefit plan, or to act on behalf of an employee benefit plan, to purchase Corporate Units (and the securities underlying the Corporate Units) should consult its own counsel regarding the potential applicability of ERISA, the Code and/or Similar Law to such investment, the potential consequences in its specific circumstances, and whether any exemption or exemptions would be applicable and should determine on its own whether all conditions of such exemption or exemptions have been satisfied. See "ERISA Considerations."

What are the uses of proceeds from the offering?

        We estimate that the net proceeds from the sale of the Equity Units in this offering will be approximately $250.5 million (approximately $288.3 million if the underwriters exercise their option in full to purchase additional Equity Units), after deducting the underwriting discounts and commissions and estimated offering expenses.

        In addition, we estimate that we will receive net proceeds, after deducting underwriting discounts and commissions and estimated offering expenses, of approximately $212.4 million from our concurrent common stock offering (approximately $244.5 million if the underwriters of such offering exercise in full their option to purchase additional shares of common stock). The concurrent common stock offering is not contingent on the completion of this offering and this offering is not contingent on the completion of the concurrent common stock offering.

        We intend to use the net proceeds from this offering, together with cash on hand and proceeds from the concurrent offering of common stock and new debt to fund a portion of the cash consideration payable in connection with the Transaction. However, the consummation of this offering is not conditioned on the closing of the Transaction. If we do not consummate the Transaction, we will retain broad discretion to use all of the net proceeds from this offering for general corporate purposes. See "Use of Proceeds" in this prospectus supplement.

What are the risks relating to the Equity Units?

        See "Risk Factors" and the risk factors set forth in the documents and reports filed with the SEC that are incorporated by reference in this prospectus supplement and in the accompanying base prospectus, including the risk factors set forth under "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2014, as amended by Form 10-K/A filed on August 7, 2015, and under "Risk Factors" in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2015, before you make an investment decision pursuant to this prospectus supplement and the accompanying base prospectus.

The Offering—Explanatory Diagrams

        The following diagrams illustrate some of the key features of the purchase contracts and the undivided beneficial ownership interests in RSNs, Corporate Units and Treasury Units.

Corporate Units

        A Corporate Unit consists of two components as described below:

(1)

Contract adjustment payments may be deferred as described under "Description of the Purchase Contracts—Contract Adjustment Payments" below.

(2)

Each owner of an undivided beneficial ownership interest in RSNs will be entitled to 1/20, or 5%, of each interest payment paid in respect of a $1,000 principal amount RSN.

(3)

Interest payments may be deferred as described under "Description of the Remarketable Junior Subordinated Notes—Option to Defer Interest Payments" below. In connection with any successful remarketing of the RSNs, the interest deferral provisions will cease to apply to the RSNs.

(4)

RSNs will be issued in minimum denominations of $1,000, except in limited circumstances following a termination event. Each undivided beneficial ownership interest in RSNs represents a 1/20, or 5%, undivided beneficial ownership interest in a RSN having a principal amount of $1,000.

        The holder of a Corporate Unit owns the 1/20, or 5%, undivided beneficial ownership interest in an RSN having a principal amount of $1,000 that forms a part of the Corporate Unit, but will pledge it to us through the collateral agent to secure its obligations under the related purchase contract.

        If the Treasury portfolio has replaced the RSNs as a result of a successful optional remarketing, the applicable ownership interests in the Treasury portfolio or cash, as applicable, will replace the RSNs as a component of the Corporate Unit.

Treasury Units

        A Treasury Unit consists of two components as described below:(1)

(1)

Treasury Units may only be created in integral multiples of 20 Corporate Units. As a result, the creation of 20 Treasury Units will release $1,000 principal amount of the RSNs held by the collateral agent. During a blackout period or following a successful remarketing, you may not create Treasury Units or recreate Corporate Units.

(2)

Contract adjustment payments may be deferred as described under "Description of the Purchase Contracts—Contract Adjustment Payments" below.

        The holder of a Treasury Unit owns the 1/20, or 5%, undivided beneficial ownership interest in the Treasury security that forms a part of the Treasury Unit, but will pledge it to us through the collateral agent to secure its obligation under the related purchase contract.

Purchase Contract

        Corporate Units and Treasury Units both include a purchase contract under which the holder agrees to purchase shares of our common stock on the purchase contract settlement date. In addition,

the purchase contracts require us to make contract adjustment payments as shown in the diagrams on the preceding pages.

(1)

The "reference price" is $40.25, which will be the public offering price of our common stock in the concurrent common stock offering.

(2)

The "threshold appreciation price" is equal to $50 divided by the minimum settlement rate (such quotient rounded to the nearest $0.0001), which is $47.2938 and represents appreciation of approximately 17.5% over the reference price.

(3)

If the applicable market value of our common stock is less than or equal to the reference price of $40.25, 1.2422 shares of our common stock (subject to adjustment).

(4)

If the applicable market value of our common stock is greater than the reference price and less than the threshold appreciation price of $47.2938, the number of shares of our common stock to be delivered to a holder of an Equity Unit will be calculated by dividing the stated amount of $50 by the applicable market value, rounded to the nearest ten thousandth of a share (subject to adjustment).

(5)

If the applicable market value of our common stock is greater than or equal to the threshold appreciation price, the number of shares of our common stock to be delivered to a holder of an Equity Unit will be 1.0572 shares (subject to adjustment).

(6)

The "applicable market value" means the average VWAP of our common stock for the trading days during the 20 consecutive scheduled trading day period ending on the third scheduled trading day immediately preceding the purchase contract settlement date (subject to adjustment as described herein if a market disruption event occurs).

The RSNs

        The RSNs have the terms described below:

(1)

Interest payments may be deferred as described under "Description of the Remarketable Junior Subordinated Notes—Option to Defer Interest Payments" and interest payment dates will be adjusted in a successful remarketing as described under "Description of the Remarketable Junior Subordinated Notes—Remarketing." In connection with any successful remarketing of the RSNs, the interest deferral provisions will cease to apply to the RSNs.

(2)

Following any successful remarketing of the RSNs, the interest rate on the RSNs will be reset, interest will be payable on a semi-annual basis, and we will cease to have the ability to redeem the RSNs at our option or defer interest payments on the RSNs, all as described under "Description of the Purchase Contracts—Remarketing."

Transforming Corporate Units into Treasury Units and RSNs

(1)

Each holder will own a 1/20, or 5%, undivided beneficial ownership interest in, and will be entitled to a corresponding portion of each interest payment payable in respect of, an RSN having a principal amount of $1,000.

(2)

RSNs will be issued in minimum denominations of $1,000 and integral multiples thereof, except in limited circumstances following a termination event. Following any successful remarketing of the RSNs, the interest rate on the RSNs will be reset, interest will be payable on a semi-annual basis, and we will cease to have the ability to redeem the RSNs at our option or defer interest payments on the RSNs, all as described under "Description of the Purchase Contracts—Remarketing."

(3)

Interest payments may be deferred as described in this prospectus supplement and interest payment dates will be adjusted in a successful remarketing as described under "Description of the Remarketable Junior Subordinated Notes—Option to Defer Interest Payments." In connection with any successful remarketing of the RSNs, the interest deferral provisions will cease to apply to the RSNs.

(4)

Contract adjustment payments may be deferred as described under "Description of the Purchase Contracts—Remarketing."

        The diagram above describes each of a Corporate Unit, a Treasury Unit and a separate RSN.

•

Because the RSNs and the Treasury securities are issued in minimum denominations of $1,000, holders of Corporate Units may only create Treasury Units in integral multiples of 20 Corporate Units.



•

To create 20 Treasury Units, a holder separates 20 Corporate Units into their two components—20 purchase contracts and an RSN having a principal amount of $1,000—and then combines the

purchase contracts with a Treasury security having a principal amount at maturity of $1,000 that matures on October 31, 2018.

•

The RSN, which is no longer a component of Corporate Units, is released from the pledge under the purchase contract and pledge agreement and delivered to the holder and is tradable as a separate security.



•

A holder owns the Treasury security that forms a part of the 20 Treasury Units but will pledge it to us through the collateral agent to secure its obligation under the related purchase contract.



•

The Treasury security together with the 20 purchase contracts constitute 20 Treasury Units.



•

During a blackout period or following a successful remarketing, you may not create Treasury Units or recreate Corporate Units.



•

Unless a blackout period is occurring or there has been a successful remarketing, the holder can also transform 20 Treasury Units and an RSN having a principal amount of $1,000 into 20 Corporate Units. Following that transformation, the Treasury security, which will no longer be a component of the Treasury Unit, will be released from the pledge under the purchase contract and pledge agreement and delivered to the holder and will be tradable as a separate security.

Illustrative Remarketing Timeline

        The following timeline is for illustrative purposes only. The dates in this timeline are based on the time periods set forth in the purchase contract and pledge agreement and the form of remarketing agreement that will be an exhibit to the purchase contract and pledge agreement. This timeline assumes that we will elect to conduct an optional remarketing during the maximum permissible optional remarketing period.

Summary Historical and Pro Forma Financial Information

        The following tables set forth certain historical financial information for us, as well as certain pro forma financial information after giving effect to the Transaction.

Our Summary Historical Financial Information

        The following tables set forth, for the periods and at the dates indicated, our summary consolidated financial information. We have derived the summary consolidated income statement information for each of the three years in the period ended December 31, 2014, and the summary consolidated balance sheet information at December 31, 2014 and December 31, 2013 from our audited consolidated financial statements incorporated by reference in this prospectus supplement. We have derived the summary consolidated income information and the other financial information for the nine months ended September 30, 2015 and September 30, 2014, and the summary consolidated balance sheet information at September 30, 2015 and September 30, 2014, from our unaudited consolidated financial statements incorporated by reference in this prospectus supplement. Historical results are not indicative of the results to be expected in the future. In addition, our results for the nine months ended September 30, 2015, are not necessarily indicative of results expected for the full year ending December 31, 2015. This summary consolidated financial information should be read in conjunction with "Management's Discussion and Analysis of Financial Condition and Results of Operations" and our financial statements and related notes in our Annual Report on Form 10-K/A for the year ended December 31, 2014 and our Quarterly Report on Form 10-Q for the quarter ended September 30, 2015, which are incorporated by reference in this prospectus supplement.

Non-GAAP Financial Measures

        The body of accounting principles generally accepted in the United States is commonly referred to as "GAAP." A non-GAAP financial measure is generally defined by the SEC as one that purports to measure historical or future financial performance, financial position or cash flows, but excludes or includes amounts that would not be so adjusted in the most comparable GAAP measures. In this prospectus supplement, we disclose net income, as adjusted, pro forma net income, as adjusted and EBITDA, as adjusted, and pro forma EBITDA, as adjusted, each of which is a non-GAAP financial measure.

Income from Continuing Operations and Net Income (loss), as Adjusted

        In addition to presenting its earnings information in conformity with GAAP, the Company has provided non-GAAP earnings data reflecting adjustments for special items as specified in the GAAP to non-GAAP adjustment reconciliation table below. Income from Continuing Operations, as adjusted, and Net income (loss), as adjusted, are defined as Income from Continuing Operations, and Net income (loss), adjusted for expenses and gains that the Company believes do not reflect the Company's core operating performance. The Company believes that non-GAAP financial measures are useful to investors because the items excluded are not indicative of the Company's continuing operating results. The Company's management uses these non-GAAP financial measures as an indicator for planning and forecasting future periods. These non-GAAP measures have limitations as analytical tools and should not be considered in isolation or as a substitute for analysis of our results as reported under GAAP. The presentation of these non-GAAP financial measures should not be construed as an inference that future results will not be affected by unusual, non-routine, or non-recurring items.

EBITDA and EBITDA, as adjusted

        We believe that earnings before interest, income taxes, depreciation and amortization (EBITDA) and EBITDA, as adjusted (EBITDA adjusted for special items as defined by management), both

non-GAAP measures, are important supplemental measures of operating performance. We believe EBITDA and EBITDA, as adjusted, when considered with measures calculated in accordance with GAAP, give investors a more complete understanding of operating results before the impact of investing and financing transactions and income taxes. We have chosen to provide this information to investors to enable them to perform more meaningful comparisons of past and present operating results and as a means to evaluate the results of core on-going operations.

        Our presentation of EBITDA may be different from the presentation used by other companies and, therefore, comparability may be limited. Depreciation and amortization expense, interest expense, income taxes and other items have been and will be incurred and are not reflected in the presentation of EBITDA. Each of these items should also be considered in the overall evaluation of our results. Additionally, EBITDA does not consider capital expenditures and other investing activities and should not be considered a measure of our liquidity. We compensate for these limitations by providing relevant disclosure of our depreciation and amortization, interest and income taxes, capital expenditures and other items both in our reconciliation to the GAAP financial measures and in our consolidated financial statements, all of which should be considered when evaluating our performance.

        Reconciliations of EBITDA, as adjusted (non-GAAP), and net income, as adjusted (non-GAAP) to the Company's most directly comparable GAAP measures are provided below.

Pro forma net income, as adjusted, EBITDA and EBITDA, as adjusted

        In addition, the Company has presented pro forma net income, as adjusted (non-GAAP) and pro forma EBITDA, as adjusted (non-GAAP), which represent net income, as adjusted (non-GAAP) and EBITDA, as adjusted (non-GAAP), respectively, taking into account pro forma adjustments with respect to the acquisitions of SourceGas, as described below under "—Summary Unaudited Pro Forma Financial Information." The same considerations that are described above with respect to net income, as adjusted (non-GAAP) and EBITDA, as adjusted (non-GAAP) apply to pro forma net income, as adjusted (non-GAAP) and pro forma EBITDA, as adjusted (non-GAAP).

        The following table provides reconciliations of pro forma net income, as adjusted (non-GAAP) and pro forma EBITDA, as adjusted (non-GAAP), to the Company's most directly comparable pro forma GAAP measures for the year ended December 31, 2014 and the nine months ended September 30, 2015.

Summary Unaudited Pro Forma Financial Information

        The following tables set forth, for the periods and at the dates indicated, summary unaudited pro forma financial information for BHC after giving effect to the Transaction. The summary unaudited pro forma income statement information for the year ended December 31, 2014 and for the nine months ended September 30, 2015 gives effect to the Transaction as if it was completed on January 1, 2014. The summary unaudited pro forma balance sheet information as of September 30, 2015 gives effect to the Transaction as if it were completed on such date. We have derived this summary unaudited pro forma combined condensed financial information from the unaudited pro forma combined condensed financial statements contained in our Current Report on Form 8-K filed with the SEC on November 16, 2015, which is incorporated by reference in this prospectus supplement.

        The combined historical consolidated financial information has been adjusted in the summary unaudited pro forma financial information below to give effect to pro forma events that are:

•

directly attributable to the Transaction;



•

factually supportable; and



•

with respect to income statement information, expected to have a continuing impact on the combined results of BHC and SourceGas.

        The summary unaudited pro forma financial information below does not reflect any cost savings (or associated costs to achieve such savings) from operating efficiencies or restructuring that could result from the Transaction. Further, the summary unaudited pro forma financial information does not reflect the effect of any regulatory actions that may impact the unaudited pro forma combined condensed financial statements when the Transaction is completed. The unaudited pro forma income statement information reflects adjustments to remove the effect of transaction costs associated with the Transaction that have been incurred by BHC and are included in its historical financial statements. Certain amounts in SourceGas's historical balance sheets and statements of income have been reclassified to conform to BHC's presentation in the unaudited pro forma combined condensed financial statements.

        Among other things, the summary unaudited pro forma information, and the unaudited pro forma combined condensed financial statements from which it is derived, reflects (i) an assumed $233.0 million of borrowings under our credit facility (with a corresponding increase in cash), (ii) an assumption that we will draw $450.0 million of short-term debt under the Bridge Term Loan Agreement in lieu of the $450.0 million of long-term debt from a proposed future debt offering, as described in Note 3 (Financing the Acquisition) to the unaudited pro forma combined condensed financial statements and (iii) an assumed $245.6 million of gross proceeds from the concurrent common stock offering. However, we currently expect to issue long-term debt in a proposed future debt offering in lieu of drawing under the Bridge Term Loan Agreement and to draw on our credit facility only to the extent necessary to fund the remaining balance of the purchase price for the Transaction. In addition, the actual gross proceeds of the concurrent common stock offering, excluding any proceeds of the underwriters' exercise of their option to purchase additional shares, will be $221.4 million. As a result, the sources and uses information described above and under "Use of Proceeds" reflects an assumption that we will finance the acquisition through a draw under our credit facility in the amount of $57.6 million and the issuance of $450.0 million of long-term debt (in addition to the proceeds from this offering and the concurrent common stock offering and assuming the continuation of $873.7 million of SourceGas's indebtedness).

        Assumptions and estimates underlying the pro forma adjustments are described in the notes accompanying the unaudited pro forma combined condensed financial statements incorporated by reference in this prospectus supplement, which should be read in connection with the summary unaudited pro forma financial information set forth below. Because the unaudited pro forma combined condensed financial statements have been prepared in advance of the completion of the Transaction, the final amounts recorded upon closing may differ materially from the information presented. These estimates are subject to change as a result of market conditions, further review of the assets acquired and liabilities assumed and additional information available at the time of the closing of the Transaction, among other things.

        The summary unaudited pro forma financial information below has been presented for illustrative purposes only and is not necessarily indicative of results of operations and financial position that would have been achieved had the pro forma events taken place on the dates indicated, or the future consolidated results of operations or financial position of the combined company. In addition, results

for the nine months ended September 30, 2015 are not necessarily indicative of results expected for the full year ending December 31, 2015.