Rio Del Lago 100 Mile Endurance Run
Granite Bay, United States • 1 Nov 2025
The Rio Del Lago 100 Mile Endurance Run is a premier ultramarathon held annually in the scenic Sierra Nevada Foothills near Folsom, California, about 40 minutes east of Sacramento. The challenging 100-mile course features approximately 13,874 feet of elevation gain and loss, traversing diverse terrain including oak woodlands, meadows, single-track trails, paved bike paths, and historic sites like Folsom Prison and No Hands Bridge. The route combines sections of the American River 50 and Way Too Cool 50K races, offering a mix of climbs, descents, and spectacular views around Folsom Lake and Auburn.
A 50K race option is also available on part of the course. The event is well-supported with themed aid stations, drop bags, and enthusiastic volunteers, creating a vibrant and supportive atmosphere for both novice and veteran ultrarunners. It serves as a qualifier for the Western States 100 and includes post-race festivities and awards. Visit the organization's website for the most recent information.