The Western States Endurance Run is one of the oldest ultra trail events in the world and certainly one of the most challenging. The Run is conducted along the Western States Trail starting at Squaw Valley, California, and ending in Auburn, California, a total of 100 miles. The trail ascends from the Squaw Valley floor (elevation 6,200 feet) to Emigrant Pass (elevation 8,750 feet), a climb of 2,550 vertical feet in the first 4� miles. From the pass, following the original trails used by the gold and silver miners of the 1850's, runners travel west, climbing another 15,540 feet and descending 22,970 feet before reaching Auburn.