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
Trail running glossary

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.

Arc of Attrition

4 Race Events100 Mile, 100K, 50K, 25K

UTMB

Porthtowan, England, United Kingdom

Course map for Arc of Attrition Arc 100

Arc of Attrition Arc 100

Jan 22, 2027

100 MileCrew

Course map for Arc of Attrition Arc 12

Arc of Attrition Arc 12

Jan 24, 2027

25K

Course map for Arc of Attrition Arc 25

Arc of Attrition Arc 25

Jan 24, 2027

50K

Course map for Arc of Attrition Arc 50

Arc of Attrition Arc 50

Jan 23, 2027

100K