Upcoming Trail Running 100Ks

Endurance Grid lists thirty-four trail running 100Ks across the US, from September 2026 to October 2027 across 11 states.

34
Races
11
States

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

How many 100K trail running races are there in the US?
Endurance Grid's Race Calendar lists 34 upcoming 100K trail running races across 11 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, New Jersey, and Utah.