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

GENERATION FACILITIES 

RAPID CITY, SD — August 6, 2012 —Black Hills Corp. (NYSE: BKH) today announced that utility subsidiaries 

Black Hills Energy – Colorado Electric and Black Hills Power are suspending operations at some of the company’s

older coal-fired and natural-gas-fired facilities this 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 operations at year-end 

2012. Black Hills Power’s coal-fired unit at the Ben French power plant in Rapid City, S.D., is scheduled to suspend 

operations on Aug. 31, 2012. Suspension of operations requires the units to be available to generate electricity when 

necessary, especially during hot summer months when customers are using the most energy. 

“We are committed to providing our customers with reliable 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 identified an opportunity to make changes to our resource 

portfolio by suspending operations at some of our older generating facilities in advance of permanently retiring 

those plants.”

To comply with environmental standards, including new U.S. Environmental Protection Agency regulations and 

Colorado’s Clean Air – Clean Jobs Act, Black Hills Power and Black Hills Energy – Colorado Electric plan to 

permanently retire 124 megawatts of coal-fired generating facilities in Colorado, South Dakota, and Wyoming. 

Retrofitting the facilities with the emissions controls to meet current regulations is not economical. The plants to be 

retired and projected retirement dates include: 

· The 42 MW coal-fired W.N. Clark plant on Dec. 31, 2013. 

· The 25 MW coal-fired unit at the Ben French power plant, as well as the 34.5 MW Osage and 22 MW Neil 

Simpson 1 coal-fired power plants on March 21, 2014. 

“Our industry continues to face increasingly stringent environmental regulations and changing energy demands 

which drive up costs for customers. Our company is working every day to balance these changes while improving 

our business to better serve our customers,” Emery said. “Our forward-looking approach and outstanding track 

record of reliability has been the legacy of our business model for the past 130 years. We work diligently 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 plan with the Colorado 

Public Utilities Commission to address customers’ energy needs during the next six years. After a thorough 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 operating in 2016, to replace the electricity produced by W.N. Clark. 

On July 31, 2012, Black Hills Power received certificate of public convenience and necessity approval to build the 

Cheyenne Prairie Generating Station, a new natural-gas-fired generating plant. The new facility will account for the 

capacity deficit from the three coal-fired plants Black Hills Power is retiring. The new plant will be jointly owned 

with Black Hills Power’s sister utility, Cheyenne Light, Fuel & Power in Cheyenne, 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 customers in 21 

southeastern Colorado communities. Black Hills Energy 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 for more than 

128 years. The electric utility serves 68,000 customers in 34 communities in western South Dakota, northeastern 

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 offices in Denver and Papillion, Neb. 

The company serves 765,000 natural gas and electric utility customers in Colorado, Iowa, Kansas, Montana, 

Nebraska, South Dakota and Wyoming. The company’s non-regulated businesses generate wholesale electricity and 

produce natural gas, oil and coal. Black Hills’ 2,000 employees partner to produce results that are improving life 

with energy. More information is available at www.blackhillscorp.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