Grindstone 100K is the 100km ultra trail at Grindstone Trail Running Festival by UTMB 2027 (Natural Chimneys Park, United States). The race starts on September 25, 2027 at 06:00 AM. It starts in Natural Chimneys Park. The time limit is 18 h.
Hold a steady pace and save energy for every section.
The course climbs 3350m+. With 34m/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.
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.
This page has 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 2027Grindstone 100M (167km)·Grindstone 50K (50.0km)·Grindstone 21K (21.0km)
Other editions of Grindstone 100K2026·2025
Official websitegrindstone.utmb.world