Lost Sierra Endurance Race

Lost Sierra Endurance Race : July 25, 2026, Downieville, CA

The event is a trail endurance race in the northern Sierra Nevada near Downieville with three distances:

• 100K
• 50K
• 25K

Courses, aid, and surface

The 100K is an out-and-back route that reaches Plumas-Eureka State Park and includes five unique aid stations (nine total stops). Its listed elevation gain is 10,780 ft and the course is nearly all singletrack with a mix of rocky and smooth trails and four major climbs. The 50K is a point-to-point route from Plumas-Eureka State Park to Downieville, with four unique aid stations and 5,360 ft of elevation gain; it includes two major climbs and a long descent near the finish. The 25K is a looped course around local canyons using First, Second, and Third Divide Trails, with 2,330 ft of elevation gain and mostly singletrack with little gravel road.

All aid stations are stocked with water, hydration mix, and light food; Aid #1, Aid #2, and Aid #5 offer warm foods. Trail surface breakdown is approximately 70% alpine singletrack, 20% mountain bike singletrack, and 10% dirt/gravel/paved road.

Logistics and rules

100K runners must carry a pack or hydration vest, a space blanket, and a headlamp for the race. Poles are allowed. Pacers are permitted for 100K runners on the return at specified aid stations; drop-bag access and crew locations vary by distance. A shuttle is provided for 50K starters for a fee; there is no post-race shuttle. Lodging in Downieville is limited and on-site tent camping at the start area is not a formal campground.

A donation-match program offers a future-race discount when donations are made to selected nonprofit partners; matches are up to $40 or 25% of the registration fee. All finishers receive event apparel and distance-specific finish awards. Visit the organization's website for the most recent information.