Sean O'Brien 100K

JAN

30

2027

Trail races in Calabasas, CA on January 30, 2027 offering 100K, 50 mile, 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

This trail running event takes place on January 30, 2027 in Calabasas, California, at 1925 Las Virgenes Road. Multiple race distances are offered on the same day on local trails near the listed address.

Distances offered:

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

The 100K is listed as a 2026 WS100 qualifier. Registration opens on Wednesday, July 1, 2026 at 6:00 AM PT. Additional event materials reference trail views and specific mile markers along the course.

Practical details such as precise start logistics, aid station placement, and exact course profile are not provided here. The event page includes a website reference and map coordinates for the venue address. 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