Lost Sierra Endurance Race

Lost Sierra Endurance Race - July 25, 2026

The Lost Sierra Endurance Race takes place in and around Downieville, California. The event offers three trail distances:

• 100K out-and-back from downtown Downieville to Plumas-Eureka/Blairsden and back
• 50K point-to-point from Plumas-Eureka State Park to Downieville
• 25K loop starting and finishing in Downieville through lower river canyons

Courses travel through river canyons, alpine ridgelines, singletrack, mountain lakes, and granite ridges. The 100K route follows the Third Divide, Pacific Crest Trail, and Lakes Basin Trails and climbs thousands of feet between Downieville and Johnsville / Blairsden. A post-race gathering takes place at the finish line.

Aid station and support details vary by distance. The 100K includes five unique aid stations (nine stops total) with crew access at Aid 2, Aid 4, and Aid 5. The 50K lists four aid stations with a crew access point at Lavezzola Road. The 25K has one formal aid station plus brief water stops.

Safety and support rules: 100K runners are required to carry a headlamp, a space blanket, and a vest or pack; organizers also note a water bottle for the remote course. Running poles are permitted. Pacers are allowed on the 100K return at specified aid stations; no pacer shuttle is provided. Cutoff totals are 11 hours for the 50K and 20 hours for the 100K.

The Unity Initiative associated with the event supports selected nonprofit partners. Donations made in 2025-2026 may be matched up to $40 or 25% of the registration fee. Selected partners include Placer Food Bank, Sacramento Food Bank, CASA (Sacramento and Placer), AcademySTAY, Sierra Club of California, Placer Land Trust, and the ACLU. Visit the organization's website for the most recent information.