Calabasas, CA, United States · Saturday, January 23, 2027

Fixed Distance 50 mi

Sean OBrien 50 Mile Trail Race

115 days away

80 km Distance

3,000 m Climbing

8.5 Grit · Elite / extreme

34.1578° N, 118.6384° W © OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Climbing rate 38 m / km Rolling. Moderate undulations. Requires consistent effort across varying grades.

Time limit 15 hours 11:15 min/km average. Generous. Walkable throughout for most of the field. About average for a 50 mi. Measured against 471 races of the same distance. Cut-off calculator →

Field size ~69 Mid-sized. Company early, well spread out by halfway.

DUV results for the 2026 edition (50mi) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, January

Daytime high 17°C

Night low 10°C

Rainfall Showers likely

Daylight 10 h 17 m of light

Regional 2001-2020 average for January — NASA POWER, grid elevation 183 m. Not a forecast.

Results history

Year	Race	Finishers	Men's winner	Women's winner
2026	50mi	69	Cody Logan · 09:24:11	Diona Fulton · 10:18:11
2025	50mi	40	Chase Wirtz · 06:10:34	Holly Ryerson · 09:41:12
2024	50mi	55	Walter Escalante · 09:05:10	Barbara George Thomson · 10:37:37
2023	50mi	67	Nicholas Allen · 08:25:30	Jennifer Benna · 09:54:30
2022	50mi	57	Jake Vail · 09:00:56	Cynthia Chiu · 09:30:02
2021	50mi	37	Joachim Cassel · 09:16:11	Frances Tennant · 12:17:13
2020	50mi	155	Dylan Bowman · 07:05:32	Stacia Watson · 10:18:32
2018	50mi	112	Ruperto Romero · 08:14:48	Kristin (Krissy) Moehl · 09:29:42
2017	50mi	87	Matthew Zupan · 07:47:10	Brianna Rogers · 09:37:11
2016	50mi	62	Karl Stutelberg · 08:48:39	Jonnah Perkins · 09:38:58

The field grew 73% between 2025 (40) and 2026 (69). 30% of the 2026 field were women.

DUV results for the 2026 edition (50mi) — 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 rolling 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 80 km of trail with 3,000 m of ascent.

Trail Running Shoes 38 m of climb per kilometre — grip and rock protection before cushioning.
Race Nutrition 80 km of self-supported fuelling between aid stations.
Hydration Vests Pole attachment and chest-strap stability on steep ground.
Trekking Poles 3,000 m of ascent to walk up.
Headlamps A 15 h limit puts you out there after dark.

Adidas

Terrex Agravic Speed Ultra

RunRepeat found the Adidas Terrex Agravic Speed Ultra to be perfect for midfoot and forefoot strikers, while iRunFar noted that the shoe feels incredibly effici…

★★★★★ 4.5

Asics

Sport Hydration Mix

Clean electrolyte drink mix with real fruit flavor. Low sugar.

$20 ★★★★★ 4.5

Nathan

VaporKrar 12L

12L race vest co-designed with ultra champion Rob Krar, with insulated bladder pocket.

$170 ★★★★★ 4.6

Komperdell

Carbon Ultralight Vario 4

4-section folding carbon poles with compact pack size for mandatory gear.

$160 ★★★★★ 4.5

Petzl

NAO RL

1500-lumen reactive lighting headlamp with 15-hour runtime. Automatic brightness adjustment.

$150 ★★★★★ 4.7

All gear guides →

Overview

The Sean OBrien 50 Mile Trail Race, a fixed-distance 50-mile trail race in Calabasas, CA, has been run 10 times since 2016. Its 3000 meters of elevation gain mean 37.5 meters of climb per kilometer, making it a hillier 50-mile race than 38% of its peers.

With a time limit of 15 hours, runners need to maintain a pace faster than 11.3 minutes per kilometer. This cut-off is tighter than 46% of 50-mile races, offering less margin than many similar events. The race typically sees a field of around 69 finishers, placing it in the larger 63% of 50-mile races.

Similar races

Other 50 mi trail ultras, closest in distance first.