The North Dakota Parks and Tourism Department (800-437-2077) offers information on the American Legacy Tour, a circular route of about six hundred miles. North from Medora it’s a couple of hours to the newly rebuilt Fort Union, once the largest and most important fur-trading post in the West. Heading east and then south, back to Bismarck, you’ll find evidence of Lewis and Clark, including a state park named for Sakakawea, the Indian woman they met in a Mandan village who became their guide. The Mandans’ round earth lodges rise as replicas in Fort Abraham Lincoln State Park. At the Knife River Indian Villages National Historic Site, sixty-five miles north of Bismarck, recent diggings have shown that an indigenous population once thought to have arrived in this area about six hundred years ago in fact took up residence here around 2000 B.C.