The Wyoming Game and Fish Department will chemically treat Cook Lake the week of September 28th, 2009. The goal of this treatment is to remove white suckers, black bullhead and green sunfish from the lake in order to produce better conditions for the variety of trout species stocked in Cook Lake each year.
Currently, the number of bullheads, suckers and sunfish found in Cook Lake result in poor trout conditions through competition for food and space. The lake will be lowered to approximately 100 acre feet prior to the treatment. Once water levels are lowered, a chemical will be applied, killing all remaining fish.
The chemical Rotenone is not harmful to humans, livestock or wildlife. However, the Cook Lake campground will be closed from September 28th through October 3rd to minimize potential use conflicts. Cook Lake has been treated with the chemical several times in the past.
This chemical is used by fisheries managers across Wyoming and the west to rehabilitate fisheries. Sheridan Fish Biologist Andrew Nikirk says, “Once treated, Cook Lake will refill throughout the winter and next spring. The lake will be stocked in June 2010 with 6,000 rainbow trout and 2,000 cutthroat trout. Fishing should be excellent for several years following treatment.”