Grindstone 100K is the 105km ultra trail at Grindstone Trail Running Festival by UTMB 2026 (Swoope, United States). The race starts on September 19, 2026 at 06:00 AM.
Hold a steady pace and save energy for every section.
The course climbs 2928m+. With 28m/km of climbing, this is a rolling, mostly runnable course. By gradient, 33% of the distance is uphill, 31% downhill and 37% flat. The longest climb runs 17.4km at an average 4.3% grade (750m of vertical). The longest descent runs 11.0km at an average 9.3% grade (1025m of vertical). The steepest climb averages 28.7% over 0.4km. The steepest descent drops at 21.4% over 0.5km. Surface: 55% trail, 30% smooth, 11% road, and 5% extreme. Flat-equivalent effort: 126.5 FlatKM.
The highest summit on the course is Little Bald Knob (1320m), 74.4km from the start. Other named summits along the route: Hankey Mountain (1051m). The course also passes close to Sand Spring Mountain (1137m).
Poles bring little benefit here: only about 9.2km of pole-friendly terrain.
Quad damage risk is moderate (index 35 of 100), with 29% of the load in the first half: 3 descents deserve a plan and a couple of downhill sessions before race day.
On race day, start temperatures have historically ranged from 9°C to 18°C, with around 18°C at the highest point; the chance of precipitation is about 33%. Heavy rain of 10.0mm or more falls on about 8% of days around this date.
155 finishers completed the 2026 edition. Men's winner: Guillaume Hansel (United States) in 9:19:24. Women's winner: Rachel Doxey (United States) in 12:26:54.
This page has the full results and splits, a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Grindstone 100K.
Other distances of Grindstone Trail Running Festival by UTMB 2026Grindstone 100M (169km)·Grindstone 50K (52.0km)
Other editions of Grindstone 100K2025
Official websitegrindstone.utmb.world