Start where the state began in Fort Benton, once the world's largest inland port. At the Upper Missouri River Breaks National Monument, buy a two-day admission to the Interpretive Center, Old Fort Benton, the Museum of the Upper Missouri, and the Museum of the Northern Great Plains. Spend the night right on the Missouri River in charming Fort Benton. 

The next day, go antiquing at the Virgelle Mercantile. Try horseback riding at Sky View Guest Ranch (reservations required), and see the "buffalo rock" used as a bison scratching post. Continue on the Havre to spend the night. 

Stop at Wahkpa Chu'gn Archaeological Site (June to Labor Day) to see a buffalo jump with an excavated wall of archaeological deposits, including compacted buffalo bones and skulls. See wild bison on a guided tour of the Fort Belknap Indian Reservation's buffalo reserve. (Call 1-406-353-4350 or 1-406-945-0014 for reservations.) Drive east on U.S. 2 to spend the night in Malta. 

Play paleontologist at the Great Plains Dinosaur Museum and Phillips County Museum in Malta. Take a side trip to either Bowdoin National Wildlife Refuge (follow Old U.S. 2 east) or Sleeping Buffalo Hot Springs Resort (via U.S. 2 east). Head back to Malta for another relaxing evening. 

Return to the route by taking U.S. 191 about 74 miles south to MT-66. Next is the self-guided Charles M. Russell National Wildlife Refuge auto tour through the badlands. Northwest of Lewistown, ride the Charlie Russell Chew Choo Montana dinner train (select weekend days in summer and early fall). After the train ride, continue on to Lewistown to spend the night. 

On the drive back to Fort Benton pull off at Bear Gulch Pictographs, a 313-million-year-old limestone inland sea formation with more than 3,000 drawings by ancient peoples. Spend your last night in Fort Benton.