Mark Twain is located west of St Louis, Missouri. Species found in the lake pool include the following: black bass, white bass, black crappie, white crappie, bluegill, green sunfish, channel catfish, blue catfish, flathead catfish, walleye, and several species of minnows including common carp, several species of suckers, gars, freshwater drum, and gizzard shad. The tailwater downstream of the re-regulation dam yields sizable concentrations of crappie, white bass, channel catfish, flathead catfish and walleye.