The first documented entry of Euro-Americans into western Montana was the Lewis and Clark Expedition. The Expedition left St. Louis in 1803 to explore and confirm the claim of the Louisiana Purchase from France. Under orders from President Thomas Jefferson, the group explored the Missouri River headwaters in search of a western path to the Pacific Ocean.

In 1805 on their western trek to the Pacific, they camped very near present-day Lolo, at what was called Travelers’ Rest. They followed the Lolo Trail up and over Lolo Pass, through the Bitterroot Mountains to Idaho. In 1806, the Expedition returned to the Bitterroot and Travelers’ Rest, where Lewis and Clark divided their party. Lewis led one group into the Missoula Valley, camping near Grant Creek on July 3, 1806. Following advice from Nez Perce guides, they left the Valley through the Hellgate Narrows by means of the old Salish Trail on July 4, and proceeded east up the Blackfoot River Valley.