### BLACK HILLS CORP. TO SUSPEND OPERATIONS OF OLDER COAL-FIRED

GENERATION FACILITIES

RAPID CITY, SD

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August 6, 2012

— Black Hills Corp. (NYSE: BKH) today announced that u tility subsidiaries Black Hills Energy

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Colorado Electric and Black Hills Power are suspen ding operations at some of the company’s older coal-fired and natural-gas-fired facilities t his year. Colorado Electric’s W.N. Clark coal-fired power plant in Cañon City, Colo. and natural-gas-fired steam units 5 & 6 in Pueblo, Colo. are set to suspend operatio ns at year-end 2012. Black Hills Power ’s coal-fired unit at the Ben French power plant in Rapi d City, S.D., is scheduled to suspend operations on Aug. 31, 2012. Suspension of operatio ns requires the units to be available to generate el ectricity when necessary, especially during hot summer months when customers are using the most energy.

“ We are committed to providing our customers with re liable and low- cost energy,” said David R. Emery, chairman, president and chief executive officer of BHC. “After a thorough analysis of new environmental regulations, coupled with changing market and operating conditions, we i dentified an opportunity to make changes to our reso urce portfolio by suspending operations at some of our o lder generating facilities in advance of permanentl y retiring those plants. ”

To comply with environmental standards, including n ew U.S. Environmental Protection Agency regulations and Colorado ’s Clean Air

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Clean Jobs Act, Black Hills Power and Black Hills Energy

– Colorado Electric plan to permanently retire 124 megawatts of coal-fired gene rating facilities in Colorado, South Dakota, and Wy oming. Retrofitting the facilities with the emissions cont rols to meet current regulations is not economical. T he plants to be retired and projected retirement dates include:

· The 42 MW coal-fired W.N. Clark plant on Dec. 31, 2 013.

· The 25 MW coal-fired unit at the Ben French power pl ant, as well as the 34.5 MW Osage and 22 MW Neil Simpson 1 coal-fired power plants on March 21, 2014

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“Our indus try continues to face increasingly stringent environ mental regulations and changing energy demands which drive up costs for customers. Our company is working every day to balance these changes while im proving our business to better serve our customers,” E mery said . “ Our forward-looking approach and outstanding track record of reliability has been the legacy of our bu siness model for the past 130 years. We work diligen tly to provide our customers with the clean, reliable energy they need in the most cost-effective manner possible .”

On July 30, 2012, Black Hills Energy

– Colorado Electric filed a new electric resource pl an with the Colorado Public Utilities Commission to address customers’ energy needs during the next six years. After a th orough analysis of available options, and considering the Colorado PUC ’s denial of the company’s 2011 request to construct an 88 MW natural-gas-fired turbine, Black Hills Energy

– Colorado Electric proposed building a 40 MW simple -cycle, natural-gas-fired turbine, which would begin operat ing in 2016, to replace the electricity produced by W.N. Clark.

On July 31, 2012, Black Hills Power received certif icate of public convenience and necessity approval to build the Cheyenne Prairie Generating Station, a new natural- gas-fired generating plant. The new facility will acc ount for the capacity deficit from the three coal-fired plants B lack Hills Power is retiring. The new plant will be jointly owned with Black Hills Power ’s sister utility, Cheyenne Light, Fuel & Power in Che yenne, Wyo., allowing Black Hills Power to share capital costs. The new facility will begin operating in late 2014.

ABOUT BLACK HILLS ENERGY Black Hills/Colorado Electric Utility Company, LP d /b/a Black Hills Energy serves 94,000 electric custo mers in 21 southeastern Colorado communities. Black Hills Ener gy is a subsidiary of Black Hills Corp.

ABOUT BLACK HILLS POWER INC.Black Hills Power is the legacy utility business of Black Hills Corp. and has been delivering energy f or more than 128 years. The electric utility serves 68,000 custom ers in 34 communities in western South Dakota, nort heastern Wyoming, and southeastern Montana.

ABOUT BLACK HILLS CORP. Black Hills Corp. (NYSE: BKH), a diversified energy company with a tradition of exemplary service and a vision to be the energy partner of choice, is based in Rapid City, S.D., and has corporate offic es in Denver and Papillion, Neb. The company serves 765,000 natural gas and electric u tility customers in Colorado, Iowa, Kansas, Montana

, Nebraska, South Dakota and Wyoming. The company’s non -regulated businesses generate wholesale electricit y and produce natural gas, oil and coal. Black Hills’ 2,00 0 employees partner to produce results that are imp roving life with energy. More information is available at www.b lackhillscorp.com.

Investor Relations: Jerome E. Nichols 605-721-1171

Media Contact: Maggie McMonigle, Colorado Electric Amy Estes, Black Hills Power 303-566-3366 303-566-3377 Media Relations Line 866-243-9002