In 1936, a 10.7-acre lake in Otsego County, Michigan, was treated with rotenone to eliminate a population of stunted yellow perch. An attempt to recover the entire population yielded 4,817 stunted perch, 27 trout in poor condition, and four species of minnows. The weight of what was assumed to be the total population was 516 pounds or slightly more than 50 pounds per acre. In 1937, an experimental planting of Montana grayling was made which was not successful owing to unauthorized introduction of bluegills about the same time. In 1941, 5,000 fingerling brook trout were stocked, but proved unable to compete with the rapidly increasing bluegill population and disappeared 4 years later. In 1943, walleyes were introduced in the hope of reducing the bluegill population to a point where survivors could make satisfactory growth.