The Missouri River doesn't look much as it did when Lewis and Clark passed through this country in the early 19th century, but few modern fishermen want the clock turned back. Monster dams have created deep, cool reservoirs that are full of gamefish and lightly fished. Trophy anglers save big for Canadian adventures, but the exchange rate (dollars spent for fish caught) is surely more sound in the Dakotas. Walleyes, of course, are the main draw. South Dakota's Lake Oahe simply begs for fishermen; the 2002 bag limit is 10 walleyes daily, and it takes an 8-pound fish to get anyone excited. North Dakota's Lake Sakakawea can be just as good, and both waters have the unique distinction of being excellent summertime fisheries. And your boat will feel tiny here; Oahe is 250 miles long and boasts 2,500 miles of shoreline, and Sakakawea is 368,000 acres. But fishing for "incidental species" (as fisheries folk here call anything that's not a marble-eye) is just as awesome. The state-record tiger muskie was caught in Lake Francis Case (South Dakota) two years ago. Trout nuts visit the Garrison Dam Tailrace (North Dakota) to tangle with browns, rainbows, and cutthroats over 10 pounds. There are smallmouth bass, northern pike, chinook salmon, channel catfish, crappies, and bluegills. For more information, contact the South Dakota Department of Game, Fish and Parks (605-773-4605; www.sdgfp.info) or the North Dakota Game and Fish Department (701-328-3000; www.discovernd.com/gnf).