San Francisco, CA, United States · Saturday, October 10, 2026

Fixed Distance 50K

Ruth Anderson Ultra 50km

10 days to go

50 km Distance

220 m Climbing

2.8 Grit · Entry level

37.7749° N, 122.4194° W © OpenFreeMap © OpenMapTiles Data from OpenStreetMap

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.

Results history

Year	Race	Finishers	Men's winner	Women's winner
2025	50km	51	Anthony Fagundes · 03:12:44	Brooke Bray · 04:05:09
2024	50km	64	David Cisewski · 03:13:15	Mallory Servais · 03:53:30
2023	50km	60	Jonah Backstrom · 03:32:02	Brooke Bray · 03:59:46
2022	50km	54	C.J. Albertson · 02:38:43	Verity Breen · 04:00:03
2021	50km	56	Oliver Chan · 03:47:15	Emi Yasaka · 04:15:26
2019	50km	36	Loren Newman · 03:17:20	Sherry Lee · 04:02:42
2018	50km	21	Jordan Sakala · 04:06:42	Christine Chapon · 04:58:04
2017	50km	22	Jean Pommier · 03:25:19	Verity Breen · 04:06:58
2016	50km	32	Jay Hsu · 03:40:33	Anna Zielaski · 03:39:39
2015	50km	46	Enrique Henriquez · 03:21:41	Denise Fleming-Williams · 04:28:55

The field shrank 20% between 2024 (64) and 2025 (51). 25% of the 2025 field were women.

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.

The Aid Station

Course-specific beta from the community

⛰️ terrain

This is a fast & flat course. Expect fast, runnable sections where rhythm is key.

By UltraHub Expert

👟 gear

With trail terrain, choose a shoe with moderate cushioning for optimal performance.

By UltraHub Expert

Gear for this race

Chosen for 50 km of trail with 220 m of ascent.

Trail Running Shoes 50 km of trail — cushioning that is still there in the last quarter.
Race Nutrition 50 km of self-supported fuelling between aid stations.
Hydration Vests Flask capacity for 50 km, without the bounce.
GPS Watches Battery life first — a 50 km day outlasts most full-GPS modes.

Brooks

Catamount 3

RunRepeat found the Brooks Catamount 3 to have a cozier upper that enhances the overall fit, though breathability and durability could be better. iRunFar noted…

★★★★★ 4.5

Adidas

Terrex Speed Ultra

RunRepeat found the Adidas Terrex Speed Ultra to have a grippy outsole and great lockdown, while iRunFar noted that the shoe works on a variety of trail conditi…

★★★★★ 4.5

Spring Energy