Upcoming Trail Running 100Ks

Endurance Grid lists twenty-six trail running 100Ks across the US, from August 2026 to September 2027 across 9 states.

26
Races
9
States

The distance

What a 100K is

A 100K is a running race where athletes run 62.1 miles long (100 kilometers) for time.

Trail running 100Ks are busiest in October and January, with the most in Texas, Pennsylvania, Indiana, and Colorado.

Frequently Asked Questions (FAQs)

How many 100K trail running races are there in the US?+
Endurance Grid's Race Calendar lists 26 upcoming 100K trail running races across 9 states.
How far is a 100K trail running?+
A 100K is a running race where athletes run 62.1 miles long (100 kilometers) for time.
Which states have the most 100K trail running races?+
The states with the most 100K trail running races on Endurance Grid's Race Calendar are Texas, Pennsylvania, Indiana, Colorado, Illinois, and New Jersey.