The total number of adult fish in Lake Frances Case, a main steam Missouri River Reservoir, has declined since impoundment in 1952. Goldeye, channel catfish, and northern redhorse have probably remained the same; emerald shiner, white bass, walleye, and possibly flathead catfish have increased. The sauger population began to decline at about the time walleye numbers increased. Some species formerly present have become rare. Forage species in the reservoir were gizzard shad, emerald shiner, and yellow perch, but these were not present in large enough numbers to provide an abundant forage fish population.