UNITED STATES DEPARTMENT OF THE INTERIOR 



Walter J. Hickel, Secretary 



Leslie L. Glasgow, Assistant Secretary 



for Fish and Wildlife, Parks, and Marine Resources 



Charles H. Meacham, Commissioner, U.S. FISH AND WILDLIFE SERVICE 



Philip M. Roedel, Director, Bureau of Commercial Fisheries 



Limnological Study of Lower 

 Columbia River, 1967-68 



By 

 SHIRLEY M. CLARK and GEORGE R. SNYDER 



United States Fish and Wildlife Service 

 Special Scientific Report--Fisheries No. 610 



Washington, D.C. 

 July 1970 



