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Built on bad decisions in Boulder, CO.

Arc of Attrition

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

UTMB

Porthtowan, England, United Kingdom

Arc of Attrition Arc 100

Arc of Attrition Arc 100

Jan 23, 2026

Arc of Attrition Arc 12

Arc of Attrition Arc 12

Jan 25, 2026

Arc of Attrition Arc 25

Arc of Attrition Arc 25

Jan 25, 2026

Arc of Attrition Arc 50

Arc of Attrition Arc 50

Jan 24, 2026