Western States 100 Aid Station Planner

The Western States 100-Mile Endurance Run covers 161km from Olympic Valley (formerly Squaw Valley) to Auburn, California, with 5,600m of elevation gain and 7,000m of loss. First run in 1974, it is one of the oldest and most prestigious 100-mile races in the world, with a lottery entry system due to extreme demand.

The heat factor. Western States is run in late June in the Sierra Nevada and Central Valley foothills. Canyon sections between Devil's Thumb (78km) and Foresthill (97km) regularly reach 35-40°C. Heat management is the primary cause of DNFs - pace plans that ignore the heat penalty in this section consistently fail. Plan for 20-30% slower actual pace in the canyon relative to your GAP target, and prioritise ice and fluid at every aid station.

Key sections. The opening climb from Olympic Valley to the Escarpment (4km, 700m D+) sets a high effort ceiling immediately. Robinson Flat (55km) is the last major crew point before the canyons. The climb from El Dorado Creek to Michigan Bluff (75-88km) in full afternoon heat is where the race separates finishers from DNFs. Foresthill (97km) is a major psychological milestone - from here the course is more runnable.

Crew access points: Robinson Flat (55km), Michigan Bluff (88km), Foresthill (97km), Rucky Chucky (122km), Auburn Lake Trails (130km), Robie Point (158km). Drop bags allowed at several additional checkpoints - check the current race guide.

Checkpoint data approximate - verify against current official race guide at wser.org before your race.