Sean O'Brien 100K

JAN

23

2027

Trail races in Calabasas, CA on January 31, 2026 offering 100k, 50 mile, 50k, marathon and 30k distances; the 100k serves as a 2026 WS100 qualifier.

Sat 23 Jan 2027

Calabasas, California

Website

100 kilometers 50 miles 50 kilometers 26 miles 30 kilometers

Always double-check with the organizer's website! This page may contain affiliate links.

Sean O'Brien 100K/50M/50K/26.2/30K - January 31, 2026

This event is a set of trail races held in Calabasas, CA, with a listed venue at 1925 Las Virgenes Road. The program for the date includes multiple distances on trail terrain and references course viewpoint photos such as Mile 7 and Mile 15 and general trail views.

The 100k distance is designated as a 2026 WS100 qualifier. The event appears as part of a trail race series and includes marathon and shorter ultramarathon options. The page for the event lists maps and directions for the location.

Distances offered include:

100k
50 mile
50k
Marathon (26.2)
30k

The description presents factual details about location, offered distances, and the qualifier status for the 100k. No start or finish times are provided in the available information. Visit the organization's website for the most recent information.

100 km

100k

50 mi

50 Miler

50 km

50k

26 mi

Marathon

30 km

30k