ABSTRACT 



Research to appraise current fish management practices and to 

 develop improved practices was carried on in the Yellowstone National Park 

 portion of the Madison River system from 1953 to 1957. The physical, 

 chemical and biological characteristics of the Firehole, Gibbon and Madison 

 Rivers are described. 



Experiments designed to test the value of fingerling and adult 

 stocking resulted in the conclusion that fingerling stocking of brown and 

 rainbow trout does not contribute to the fishery substantially and that adult 

 stocking is of greatest value only in the season of stocking. Examination of 

 scales showed that hatchery fish are readily distinguishable from wild fish. 

 There were no differences in growth rates of wild fish in different years for 

 different rates of stocking of hatchery fish. The brown and rainbow trout 

 populations are not affected adversely by heavy introduction of hatchery 

 fingerlings of each species or of adult rainbows. Brook and brown trout and 

 whitefish are substantially underfished. 



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