In order to obtain information regarding the length of time required for trout and nongame fish to repopulate decimated stream sections following fish kills or chemical treatment, fish population data were collected during and at periodic intervals following chemical treatment of the North Fork Feather River and of Sutter and Silver King Creeks. Wild trout populations reached pretreatment levels without restocking in from 1 to 5 years. Trout populations recovered most quickly in the N. F. Feather River below Rock Creek Dam, where within one year heavy recruitment from yearling rainbow trout (Salmo gairdnerii) drifting down some 20 miles of tributaries increased the biomass of rainbow trout to a level three times greater than the pretreatment population. In Sutter and Silver King Creeks, where only limited trout numbers existed upstream from the treatment area, fish repopulation appeared to be much slower. In Silver King Creek, a high elevation meadow stream, the wild trout biomass of Piute trout (Salmo clarkia seleniris) reached pretreatment levels within 3 years, while numbers of adult trout did not reach pretreatment levels until after 4 years. In Sutter Creek, a low elevation stream, the wild rainbow trout biomass did not reach pretreatment levels until the fifth year, while numbers of wild adult rainbows reached pretreatment levels within two years.
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