Find your race Upcoming Find a Qualifier

Search Dashboard Saved Races Calendar

Helping the trail running community discover, plan for, and thrive at the world's best trail races.

Find Races

Search all trail races
Explore collections
Race series
Race qualifiers

Races by Location

Colorado trail races
California trail races
Utah trail races
Arizona trail races
Washington trail races
All US trail races

Lottery Odds

Western States 100
Hardrock 100
High Lonesome 100
UTMB
All calculators

Company

About
Roadmap
Terms of service
Privacy policy

Feedback

Send Feedback
Feature Requests
Report a Bug

© 2026 Trailrace.co. All rights reserved.

Built on bad decisions in Boulder, CO.

KH Races

Sean O'Brien Trail Runs

Jan 31, 2026

Calabasas, CA, US

50K, Marathon, 50 Mile, 100K, 30K

Sean O'Brien 50K

Sean O'Brien 50K

Jan 31, 2026

Sean O'Brien Marathon

Sean O'Brien Marathon

Jan 31, 2026

Sean O'Brien 50 Mile

Sean O'Brien 50 Mile

Jan 31, 2026

Sean O'Brien 100K

Sean O'Brien 100K

Jan 31, 2026

Sean O'Brien 30K

Sean O'Brien 30K

Jan 31, 2026