Lake Francis Case MISSOURI RIVER REGION SDMissouriRiver.com // Nearly reaching the South Dakota border, Lake Francis Case is the second biggest reservoir in the state at just over 100 miles long. The Fort Randall Dam creates this reservoir, and just north of it is National Wildlife Refuge Lake Andes . The rolling prairie terrain surrounding Lake Francis Case is a paradise for outdoor enthusiasts, hunters, and anglers. Big towns along this reservoir: Chamberain, Oacoma, Platte, Geddes, Lake Andes, Pickstown, Bonesteel. Lewis & Clark Lake This 25-mile lake sits along the South Dakota-Nebraska border, ending at Gavins Point Dam , known for its signature shoreline chalky bluffs near Yankton, and its colorful sailboats. At the northern end of the lake, the Missouri River becomes its old self, narrowing and winding like what Lewis and Clark would have seen in 1804. The area is full of parks for river recreation. Big towns along this reservoir: Pickstown, Wagner, Springfield, Yankton. Outdoor Adventure Happens Every Day Oahe West Shore Mountain Bike Trail 191