After leaving the Lakota Museum, I stopped at the impressive Lewis and Clark Information Center, just off I-90 in Chamberlain. Then I headed north on SD HWY 50. At Ft. Thompson I picked up SD HWY 34 which turns west at Mac's Corner and meets the Missouri River near the Fort George boat ramp.. Lake Case, created by the Big Bend Dam, has inundated all of the L&C sites along here. I decided to look for a more natural Missouri south of Pierre. These photos show the marshes and islands typical of the Corps' experience. Top left, looking south down the river. Left, looking north toward Pierre and looking straight across, above.