The "target area" of Chico Creek extended from the waterfall which forms the upstream limiter for both non-salmonid and anadromous fish, downstream to a washed-out fish ladder near the upper end of Iron Canyon. The "treated area" extended further downstream to a convenient site for detoxification. Treatment was partially justified by the assumption that Iron Canyon, with its non-functional fish ladder would act as a barrier to prevent recolonization of the target area by non-salmonids.
Subsequent to the treatment, excess fry from the Feather River Hatchery were planted at Ponderosa Way to try to re-establish populations. Each spring from 1987 to 1992, 100 to 500 thousand spring-run chinook salmon fry were planted. In years 1987, 1988, and 1990 from 50 to 100 thousand steelhead fry were planted.