Grindstone 21K is a 21.0 km trail race of Grindstone Trail Running Festival by UTMB 2025 in Swoope, United States. The race starts on September 19, 2025. The course climbs 518 m+ and descends 448 m−, between a low point of 409 m and a high point of 738 m. By gradient, 18% of the distance is uphill, 21% downhill and 61% flat. The longest climb runs 2.1 km at an average 12.2% grade (251 m of vertical). The longest descent runs 1.7 km at 13.4% (223 m of vertical). Surface: 35% trail, 31% road, and 22% smooth. Flat-equivalent effort: 23.8 FlatKM.
This page has the interactive elevation profile, gradient matrix, pacing and nutrition planner and weather climatology for Grindstone 21K.
Other distances of Grindstone Trail Running Festival by UTMB 2025Grindstone 100M (169 km)·Grindstone 100K (105 km)·Grindstone 50K (52.0 km)
Official websitegrindstone.utmb.world
