Exhibit 21
BLACK HILLS CORPORATION
SUBSIDIARIES
December 31, 2006
Black Hills Artesia, LLC, a Delaware limited liability company
Black Hills Cabresto Pipeline, LLC, a Delaware limited liability company
Black Hills Colorado, LLC, a Delaware limited liability company
Black Hills Energy Pipeline, LLC, a Delaware limited liability company
Black Hills Energy Resources, Inc., a South Dakota corporation
Black Hills Energy Terminal, LLC, a South Dakota limited liability company
Black Hills Energy, Inc., a South Dakota corporation
Black Hills Exploration and Production, Inc., a Wyoming corporation
Black Hills Fountain Valley, LLC, a Delaware limited liability company
Black Hills Fountain Valley II, LLC, a Colorado limited liability company
Black Hills Gas Holdings Corp., a Colorado corporation
Black Hills Gas Resources, Inc., a Colorado corporation
Black Hills Generation, Inc., a Delaware corporation
Black Hills Idaho Operations, LLC, a Delaware limited liability company
Black Hills Independent Power Fund, Inc., a Texas corporation
Black Hills Ivanpah GP, LLC, a Delaware limited liability company
Black Hills Ivanpah, LLC, a Delaware limited liability company
Black Hills Kilgore Energy Pipeline, LLC, a Delaware limited liability company
Black Hills Kilgore Pipeline Company, L.P., a Texas limited partnership
Black Hills Kilgore Pipeline, Inc., a Delaware corporation
Black Hills Midstream, LLC, a South Dakota limited liability company
Black Hills Millennium Pipeline, Inc., a South Dakota corporation
Black Hills Millennium Terminal, Inc., a South Dakota corporation
Black Hills Nevada Operations, LLC, a Delaware limited liability company
Black Hills Nevada Real Estate Holdings, LLC, a Delaware limited liability company
Black Hills Nevada, LLC, a Delaware limited liability company
Black Hills Ocotillo, LLC, a Delaware limited liability company
Black Hills Ontario, LLC, a Delaware limited liability company
Black Hills Operating Company, LLC, a Delaware limited liability company
Black Hills Pepperell Power Associates, LLC, a Delaware limited liability company
Black Hills Plateau Production, LLC, a Delaware limited liability company
Black Hills Power, Inc., a South Dakota corporation
Black Hills Service Company, LLC, a South Dakota limited liability company
Black Hills Southwest, LLC, a Delaware limited liability company
Black Hills Valmont Colorado, Inc., a Delaware corporation
Black Hills Waterville Station, LLC, a South Dakota limited liability company
Black Hills Wyoming, Inc., a Wyoming corporation
Bloomfield Glenns Ferry, Inc., a Virginia corporation
Bloomfield Idaho Management, Inc., a Delaware corporation
Bloomfield Rupert, Inc., a Virginia corporation
Buick Power, LLC, a Delaware limited liability company
Cheyenne Light, Fuel and Power Company, a Wyoming corporation
Daksoft, Inc., a South Dakota corporation
Desert Arc I, L.L.C., a Delaware limited liability company
Desert Arc II, L.L.C., a Delaware limited liability company
E-Next A Equipment Leasing Company, LLC, a Delaware limited liability company
EIF Investors, Inc., a Delaware corporation
Enserco Energy Inc., a South Dakota corporation
Fountain Valley Power, L.L.C., a Delaware limited liability company
Hamptons Power II LLC, a Delaware limited liability company
Harbor Cogeneration Company, LLC, a Delaware limited liability company
Las Vegas Cogeneration Energy Financing Company, L.L.C., a Delaware limited liability company
Las Vegas Cogeneration II, L.L.C., a Delaware limited liability company
Las Vegas Cogeneration Limited Partnership, a Nevada limited partnership
Millennium Pipeline Company, L.P., a Texas limited partnership
Millennium Terminal Company, L.P., a Texas limited partnership
Sunco, Ltd., a Limited Liability Company, a Nevada limited liability company
Varifuel, LLC, a South Dakota limited liability company
West Cascade Energy, LLC, a Delaware limited liability company
Wyodak Resources Development Corp., a Delaware corporation