Ruth Anderson Memorial Endurance Run
Lakeshore, United States • 10 Oct 2026
Event details
The Ruth Anderson Memorial Endurance Run is scheduled for October 10, 2026 and is the 39th edition since 1986. The event takes place in San Francisco, California, with Race HQ at Lake Merced Blvd. and Sunset Blvd. Online registration has a deadline in October 2026; race-day registration is available for an extra $10 if the race is not full. USATF certified course maps are available for the 50 km and 50 mile courses.
Course and logistics
The event is run on a looped course of 4.475 miles per lap on a paved bike path with dirt shoulders. There is one aid station per loop located at the start/finish area. Elevation data for the loop are provided: total climb 2,488 feet, total descent 2,555 feet, high point 94 feet, low point 29 feet, start/finish elevation 72 feet. Cutoffs for the 50-mile event require completion of 7 laps (31.1 miles) by 7 hours 30 minutes into the race and 10 laps (44.5 miles) by 10 hours 40 minutes into the race. Course records are maintained by age group for 100k, 50-mile and 50k distances. Historical results and finishing data are recorded for events dating back to 1986; the 2020 edition was cancelled due to COVID-19. Visit the organization's website for the most recent information.