Sean O'Brien 100K

JAN

30

2027

Trail races in Calabasas, California on January 30, 2027 offering 100K, 50M, 50K, marathon and 30K distances. The 100K is a 2026 WS100 qualifier and registration opens July 1, 2026.

Sat 30 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 : Calabasas, CA

The event takes place Saturday, January 30, 2027, at 1925 Las Virgenes Road in Calabasas, California. It is organized as a series of trail running distances on local trails.

Distances offered include:

100K
50 Miler
50K
Marathon (26.2)
30K

The 100K is designated as a 2026 Western States 100 (WS100) qualifier. Registration for the event opens Wednesday, July 1, 2026 at 6:00 AM Pacific Time. The event listing identifies multiple viewing locations along the course and references trail views and specific mile markers.

Information presented focuses on the race options, qualifier status for the 100K, and the event location. No start time or course technical details 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

26.2

30 km

30k