Lost Trail Pass

Lost Trail Pass is a mountain pass in the Rocky Mountains of the northwestern United States, on the border of Idaho and Montana in the Bitterroot Mountains. The pass is at an elevation of 7,014 feet (2,138 m) above sea level and is traversed by U.S. Highway 93.

Lost Trail Pass
Lost Trail Location on Idaho-Montana border Show map of USA West Lost Trail Lost Trail (Idaho) Show map of Idaho
Elevation	7,014 ft (2,138 m)
Traversed by	US 93
Location	Lemhi County, Idaho / Ravalli County, Montana, U.S.
Range	Bitterroot Mountains, Bitterroot Range, Rocky Mountains
Coordinates	45°41.6′N 113°56.9′W

The pass is about a half-mile (1 km) west of the continental divide, which retreats eastward at this point, inside Montana along the Ravalli-Beaverhead county border, toward Butte. Southeast of Lost Trail Pass, the divide straddles the state line into Yellowstone National Park and continues in Wyoming.

Entering Montana on US 93
at Lost Trail Pass

South of the pass in Idaho is the North Fork of the Salmon River, which descends with US-93 to North Fork to join the main Salmon River. In Montana, US-93 drops northward into the Bitterroot River Valley, and gradually descends towards Hamilton, Lolo, and Missoula.

In 1805 Lewis and Clark crossed the divide between Lemhi County (Idaho) and Ravalli County (Montana) approximately 1.3 miles (2 km) northwest of Lost Trail Pass to enter the Bitterroot Valley on September 4.[1] They later rested for a few days at Travelers' Rest, near present-day Lolo,[2] in preparation for their crossing over the snowy Bitterroots at Lolo Pass, back into present-day Idaho, following the Lolo Trail, north of US-12.[3]

The Lost Trail Powder Mountain ski area is at the pass, immediately west of US-93, with lifts and runs in both states.