Lolo Pass, elevation 5,233 feet (1,595 m), is a mountain pass in the western United States, in the Bitterroot Range of the northern Rocky Mountains. It is on the border between the states of Montana and Idaho, approximately 40 miles (65 km) west-southwest of Missoula, Montana. The pass was also used in 1877 during the Nez Perce War as some of the Nez Perce under Chief Joseph tried to escape the U.S. Army. Shortly after crossing the pass, the two sides clashed at the Battle of the Big Hole in Montana. * Lolo Pass, Montana side, approaching summit, westbound * Entering Montana from Lolo Pass * * *