Rio Del Lago 100 Mile Endurance Run

Granite Bay, United States • 2 Nov 2025

The Rio Del Lago 100 Mile Endurance Run is a premier ultramarathon held annually in the scenic Sierra Foothills of California, near Folsom Lake, about 40 minutes east of Sacramento. The challenging 100-mile course features approximately 13,874 feet of elevation gain and loss, traversing oak woodlands, meadows, single-track trails, and historic sites like Folsom Prison and No Hands Bridge. The route combines parts of the American River 50 and Way Too Cool 50K races, offering varied terrain suitable for both novice and veteran runners.

The event also includes a 50K race option. Aid stations provide extensive nutrition, and pacers are allowed on specific sections. The race fosters a supportive atmosphere with a post-race festival and is a qualifier for the Western States 100. Visit the organization's website for the most recent information.

Race information

100 mi
13874 m+
100 Mile Endurance Run
50 km
50k Endurance Run
Visit the organization's website for the most recent information.
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