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

Fixed Distance 100K

Sean OBrien 100 km Trail Race

115 days away

100 km Distance

4,000 m Climbing

10.0 Grit · Elite / extreme

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

What the course asks

Climbing rate 40 m / km Mountain. Significant climbing. Steep sections will require power hiking.

Time limit 16 hours 9:36 min/km average. Comfortable. Room to walk the climbs and stop at aid. About average for a 100K. Measured against 214 races of the same distance. Cut-off calculator →

Field size ~84 Mid-sized. Company early, well spread out by halfway.

DUV results for the 2026 edition (100km) — 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	100km	84	Dmitri Journist · 11:04:32	Charlotte Saunders · 12:04:33
2025	100km	70	Ryan Kiewiet · 10:32:58	Lauren Mitchell · 11:18:35
2024	100km	73	Max Jolliffe · 10:00:01	Kenzie MacPhail · 11:59:20
2023	100km	91	Ben Eysenbach · 09:02:03	Lauren Mitchell · 11:58:18
2022	100km	62	Jesse Haynes · 09:30:02	Jaclyn Foroughi · 11:47:05
2021	100km	30	Ruperto Romero · 10:11:53	Emily Sabo · 11:58:11
2020	100km	130	Daniel Kwon · 10:10:33	Luzia Bühler · 10:59:55
2018	100km	134	Florian Neuschwander · 08:48:04	Courtney Dauwalter · 09:38:17
2017	100km	137	Christopher Wehan · 08:24:35	Emily Harrison · 09:56:15
2016	100km	72	Stephen Wassather · 09:37:22	Devon Yanko · 10:27:02

The field grew 20% between 2025 (70) and 2026 (84). 23% of the 2026 field were women.

DUV results for the 2026 edition (100km) — 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 mountain 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

🥤 nutrition

For 100km+ efforts, prioritize real food at aid stations to prevent palate fatigue.

By UltraHub Expert

Gear for this race

Chosen for 100 km of trail with 4,000 m of ascent.

Trail Running Shoes 40 m of climb per kilometre — grip and rock protection before cushioning.
Race Nutrition Past 100 km the palate quits before the legs do — carry more than one flavour.
Hydration Vests Pole attachment and chest-strap stability on steep ground.
Trekking Poles 4,000 m of ascent to walk up.
Headlamps A 16 h limit puts you out there after dark.