BLACK HILLS' ENERGY COST ADJUSTMENT APPROVED BY SOUTH DAKOTA PUBLIC UTILITIES COMMISSION

Black Hills Contact Information:
Mutch Usera 605-484-1476
Media Relations 866-243-9002

Investor Relations:
Jason Ketchum 605-721-2765

RAPID CITY, SD–March 2, 2009–Black Hills Corp. (NYSE: BKH) utility subsidiary Black Hills Power announced that the South Dakota Public Utilities Commission approved its proposed Energy Cost Adjustment rate increase. The new rate, effective March 1, 2009, will impact the electric utility's South Dakota customers.

The impact to the average residential customer is an increase of about $1.68 per month or about $20.00 a year. According to the cost-sharing formula approved by the SDPUC, Black Hills Power absorbs the first $2 million in increased costs and both South Dakota customers and Black Hills Power share in absorbing costs above that amount. The increase helps the company recoup a portion of the $6.4 million increase in operating costs incurred during the period Jan. 1, 2008 through December 31, 2008.

"The ECA is necessary to help offset the increasing costs required to deliver safe, reliable electric service to our customers," said Chuck Loomis, Vice President of Operations for Black Hills Power. "Power providers are exposed to volatile fuel and purchased power prices and mining expenses, in addition to the cost of operating transmission systems required to serve the growing energy needs of our customers."

ABOUT BLACK HILLS CORPORATION
Black Hills Corp. — 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., with corporate offices in Golden, Colo., and Omaha, Neb. The company serves 750,000 utility customers in Colorado, Iowa, Kansas, Montana, Nebraska, South Dakota and Wyoming. The company’s non-regulated businesses generate wholesale electricity, produce natural gas, oil and coal, and market energy. We partner to produce results that improve life with energy. More information is available at www.blackhillscorp.com.

ABOUT BLACK HILLS POWER
Black Hills Power is the legacy business of Black Hills Corp. and has been delivering energy for more than 125 years. The electric utility serves 65,400 customers in 20 communities in western South Dakota, northeastern Wyoming and southeastern Montana. More information is available at www.blackhillspower.com.

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