San Francisco, CA, United States · Saturday, October 10, 2026
Fixed Distance 50K
Ruth Anderson Ultra 50km
24 days to go
50 km Distance
220 m Climbing
2.8 Grit · Entry level
What the course asks
Climbing rate 4 m / km
Fast & Flat. This course is relatively flat and fast. Ideal for PB attempts.
Field size ~51 Small. Long stretches with nobody in sight.
DUV results for the 2025 edition (50km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.
Typical conditions, October
Daytime high 21°C
Night low 11°C
Rainfall Mostly dry
Daylight 11 h 29 m of light
Regional 2001-2020 average for October — NASA POWER, grid elevation 87 m. Not a forecast.
The Aid Station
Course-specific beta from the community
This is a fast & flat course. Expect fast, runnable sections where rhythm is key.
With trail terrain, choose a shoe with moderate cushioning for optimal performance.
Gear for this race
Chosen for 50 km of trail with 220 m of ascent.
- Trail Running Shoes50 km of trail — cushioning that is still there in the last quarter.
- Race Nutrition50 km of self-supported fuelling between aid stations.
- Hydration VestsFlask capacity for 50 km, without the bounce.
- GPS WatchesBattery life first — a 50 km day outlasts most full-GPS modes.
Course Notes
certified 4.475 miles paved bike path with dirt shoulders (per loop)
Similar races
Other 50K trail ultras, closest in distance first.