Registration is closed
Registration opens
July 1, 2026 6:00 AM
Malibu Creek State Park
1925 Las Virgenes Road
Calabasas, CA 91302
January 29, 2027 3:30pm-6pm (no location info yet)
Sean O'Brien 100k is a qualifier for the Western States Endurance Run.
The Sean O'Brien 50 Mile is a Sterling Silver Ticket Race for Angeles Crest 100.
Malibu Creek State Park
1925 Las Virgenes Road
Calabasas, CA 91302
January 29, 2027 3:30pm-6pm (no location info yet)
This will be a cupless race. No plastic! We will not have cups at the aid stations. You must be self sufficient and carry hydration.
2022 100k | 50 Mile Results results
2015 Race Photos. Big thanks to Stepahnie Plomarity providing us with the photography.
