United States
Jan
25
Saturday
Sean o'Brien
The Sean O'Brien event offers a range of trail running distances including 100K, 50M, 50K, Marathon (26.2 miles), and 30K, taking place in Calabasas, CA. This race is notable as the 100K distance serves as a qualifier for the prestigious Western States 100 in 2026. The event is currently sold out, but interested participants can join the waitlist.
The scenic course promises beautiful views and a challenging experience for runners of all levels. Registration for the event closes shortly before the race date. Visit the organization's website for the most recent information.
Always double-check with the organizer's website – things can change, and we might have sprinted past a few details!
100 km
100K
50 mi
50 Miler
50 km
50K
30 km
30K
26.2
