Sean o'Brien

Calabasas, United States • 25 Jan 2025

The Sean O'Brien event offers a variety of trail running distances, including 100K, 50 miles, 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 2026 Western States 100. 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.

Race information

100 km
100K
50 mi
50 Miler
50 km
50K
30 km
30K
26.2
Visit the organization's website for the most recent information.
Trail runs nearby

The 4 Mile Hill Challenge is an exciting running event taking place at the Audubon Center at Debs Park in Los Angeles, California. Designed for both beginners and elite runners, the course features rolling hills and all-trail paths within a historic park setting. Participants can expect hydration st..

The Ray Miller 50/50 is a running event held in Point Mugu State Park, Malibu, CA, featuring three race distances: 50 miles, 50K, and 30K. This scenic race offers participants the chance to experience the beautiful trails of the park while challenging themselves in a competitive environment. Registr..

The Mt. Hollywood 12K Trail Run Hike is an exciting outdoor event taking place in Griffith Park, Los Angeles, featuring multiple race options including a 12K trail run/hike, an 8K run, a 5K challenge, and a kid's 2.2K run. Participants can enjoy stunning views of the Hollywood Sign, Griffith Observa..

The Boney Mountain Trail Run is an exciting running event set in the stunning Santa Monica Mountains, starting at Rancho Sierra Vista/Satwiwa National Park. Participants can choose between a challenging half-marathon course featuring creek crossings, single-track climbs, and breathtaking ocean views..

The Boney Half Marathon is an exciting trail running event set in the stunning Santa Monica Mountains, starting at Rancho Sierra Vista/Satwiwa National Park. Participants can expect a challenging course featuring creek crossings, single-track climbs, and breathtaking ocean views. This race is part o..

The Singletrack Stampede is an exciting cross-country running event featuring 10K and 22K distances, designed for runners of all skill levels. Set on the scenic Millenium Loop Trail, participants will navigate twists, turns, and challenging switchbacks while enjoying breathtaking views of the Las Vi..