Ruth Anderson Memorial Endurance Run
Lakeshore, United States • 10 Oct 2026
Event
The Ruth Anderson Memorial Endurance Run is scheduled for October 10, 2026. This is the 39th running of the event, first held in 1986. The event takes place in San Francisco with race headquarters at Lake Merced Blvd. and Sunset Blvd. Distances contested include:
- 100 km
- 50 miles
- 50 km
Race day registration may be available for an additional $10 if the event is not filled. Chip timing is provided by a timing service. The 50K and 50-mile courses are USATF certified. The event has been held most years since 1986; it was not held in 1999 and the 2020 edition was cancelled due to COVID-19.
Course and logistics
The course is a loop of 4.475 miles on a paved bike path with dirt shoulders. Aid is located once per loop at the start/finish area. Reported elevation figures for the full course include total climb of 2,488 feet, total descent of 2,555 feet, high point 94 feet, low point 29 feet, and start/finish elevation 72 feet.
For the 50-mile distance, cutoffs require completion of 7 laps (31.1 miles) by 7.5 hours into the race and 10 laps (44.5 miles) by 10 hours 40 minutes into the race. The event lists a history of starters and finishers for prior years and maintains course records by age group. Sponsors include a sports nutrition company and the local parks department. Visit the organization's website for the most recent information.