Sacagawea recognized the site where the Madison, Jefferson, and Gallatin form the mighty Missouri River as the place where her tribe was camped when the Hidatsa captured her about five years earlier. The Corps camped here on its westward journey and Clark noted in his journal, "we proceeded on a fiew miles to the three forks of the Missouri. Those three forks are nearly of a Size, the North fork appears to have the most water and must be Considered as the one best calculated for us to assend. Middle fork is quit as large about 90 yds. wide. The South fork is about 70 yds wide & falls in about 400 yards below the middle fork. Those forks appear to be verry rapid & contain some timber in their bottoms which is verry extencive."
After much deliberation, Lewis decided that the river that flowed from the southwest, the Jefferson, was the main branch of the river, so they followed it to the source of the Missouri.
On the return trip, after dividing the Corps into two groups Lewis' party headed up the Marias River and Clark's party returned to the Missouri's Headwaters on July 13, 1806. Sacagawea led them through today's Bozeman Pass and then Clark further divided his party. Sergeant Pryor and three men took the expedition's horses overland, while Clark and the others headed towards the Yellowstone to chart the river to its confluence with the Missouri in the eastern part of Montana.
Missouri Headwaters was established as a state park in 1951 due to the site's Expedition connection. Although for centuries the significant river confluence also provided an ideal camping site and hunting grounds for native nations. The three forks site was where the Blackfeet captured former Expedition member John Colter in 1808, and then allowed him to leave to convey a message to others planning to come to the headwaters: "don't". A fur trade fort occupied the site around 1810 and white settlers came to the area during the gold rush in the 1860s. In 1908, the town of Three Forks was established on a railroad line along the river. Missouri Headwaters State Park is now a National Historic Landmark, and is popular for wildlife viewing and fishing. Madison Buffalo Jump State Park, Lewis and Clark Caverns State Park, Bannack State Park, Virginia City, the Museum of the Rockies in Bozeman, and the Montana Historical Society in Helena are just a few of the many cultural attractions within a short drive.
