Three Forks, MT is a sweet little town between Billings and Helena. It has a wonderful museum which exhibits history from the region which has grown up around the three rivers which combine to form the Missouri River. It also features a statue of Sacajawea, which sits in the center of town across the street from the Sacajawea Hotel.
I visited the town after staying on a nearby ranch, on the third night of my cross country road trip.