| EXHIBIT 21   **SUBSIDIARIES OF THE REGISTRANT      WPS RESOURCE CORPORATION      
WPS RESOURCES CORPORATION *  
Wisconsin Public Service Corporation  
WPS Leasing, Inc.  
WPS Investments, LLC   
American Transmission Company LLC (12.1% ownership)  
Wisconsin Valley Improvement Company (26.9% ownership)  
Wisconsin River Power Company (66.88% ownership)   
Lakes Development Corporation  
ATC Management Inc. (12.1% ownership)   
Upper Peninsula Power Company    
WPS Visions, Inc.   
Badger Energy Services, LLC (14.29% ownership)   
Upper Peninsula Building Development Company   
Penvest, Inc.  
Superior Technologies, Inc. (33% ownership)   
WPSR Capital Trust I   
WPS Nuclear Corporation  
Nuclear Management Company, LLC (20% ownership)   
WPS Resources Capital Corporation  
WPS Energy Services, Inc.   
WPS-ESI Gas Storage, LLC (75% ownership)  
WPS Power Development, Inc.   
PDI Stoneman, Inc.    
Mid-American Power, LLC (66-2/3% ownership)   
Combined Locks Energy Center, LLC   
PDI Operations, Inc.   
Mid-American Power Ventures, LLC (75% ownership)   
Neulite Industries of Wisconsin, LLC (50% ownership)   
WPS Canada Generation, Inc. (formerly PDI Canada, Inc.)   
WPS New England Generation, Inc. (formerly PDI New England, Inc.)   
WPS Northern Nevada, LLC   
Sunbury Holdings, LLC    
Sunbury Generation, LLC    
Penfield Collieries, LLC    
WPS Westwood Generation, LLC (formerly CinCap VI, LLC)   
Renewable Fibers International, LLC (33-1/3% ownership)   
Wisconsin Woodgas LLC   
Wisconsin Energy Operations LLC (49% ownership)   
ECO Coal Pelletization #12 LLC (66-2/3% ownership)     
Brown County C-LEC, LLC (40% ownership)  
*
WPS Resources Corporation is the parent holding company. All affiliated      companies listed are 100% owned except asnoted otherwise. All affiliates      are currently active, with the exception of Mid-American Power Ventures,      LLC and Neulite Industries of Wisconsin, LLC.
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