UNITED STATES DEPARTMENT OF THE INTEJIIOR, STEWART L, UDALL, SECRET ARY 

 Stanly A. Cain, Assistan t Secretar y fo r Fish and Wildlife 

 Fish and Wildlife Service, Clarence F. Pautzke, Co mmissioner 

 Bureau of Sport Fisheries and Wildlife, John S. Gottschalk, Direct or 



CHARACTERISTICS OF FISH POPULATIONS IN 

 UPPER MISSISSIPPI RIVER BACKWATER AREAS 



By 



Lyle M. Christenson, Chief Fishery Biologist 

 Wisconsin Conservation Department, Research and Planning Division 



Madison, Wisconsin 



and 



Lloyd L. Smith, Department of Entomology, Fisheries, and Wildlife 

 University of Minnesota, St. Paul, Minnesota 



Circular 212 

 Washington, D. C. • March 1965 



