The Flathead Indians came to the Bitterroot from the west, and although they made regular trips to the plains to hunt buffalo, they made ample use of the valley’s roots, huckleberries, and fish.

In 1805 Lewis and Clark passed down the Bitterroot Valley from the south, over Lost Trail Pass. The Corps of Discovery had already crossed the Continental Divide at Lemhi only to discover that although the Salmon River in Idaho flowed into the Columbia drainage, it did so as the aptly named “River of No Return.” The Salmon was hopelessly impassable. The corps climbed up into Montana again, this time to follow the Bitterroot down to the area near Lolo Creek, where they established a favorite camping spot called Travelers’ Rest. From here the corps followed Lolo Creek up and over Lolo Pass, and down more hospitable drainages to the Columbia. The following year they retraced their trail to Travelers’ Rest. Clark and half the corps returned up the Bitterroot to cross over Gibbon Pass into the Big Hole.

Lewis is responsible for the name of the plant that gives this valley its name. While local Indians found the roots of the bitterroot both tasty and fortifying, Lewis pronounced it bitter and nauseating. His name now identifies the plant in Latin: Lewisia rediviva.

The Bitterroot Valley, with its fertile bottomland and protected climate, attracted farmers from the beginning. The discovery of gold in nearby valleys and the establishment of mining boomtowns created a demand for foodstuffs. As farmers moved into the area, they began to pressure the government to remove the Flathead from the valley, and in 1872 James Garfield, who later became the 20th president, was sent to transfer the Indians north to the Mission Valley.

Five years later the Nez Percé passed through the Bitterroot on their tragic flight across the Northwest. Under the leadership of Chief Joseph, the band of about 700 Indians and nearly 2,000 horses traveled from Idaho down Lolo Creek and up the Bitterroot toward Crow country, fleeing the army infantry. Chief Joseph vowed to the army and the Bitterroot settlers to march peaceably through the settled areas of the Bitterroot in return for unmolested passage. The offer was not accepted officially, and the Nez Percé simply skirted a hastily constructed barricade at Fort Fizzle and proceeded up the Bitterroot. No shots were fired as they passed through the valley. Once over the Continental Divide in the Big Hole, however, Col. John Gibbon and 183 men ambushed the Nez Percé at the Battle of the Big Hole.