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Grindstone 50K is a 52.0 km trail race of Grindstone Trail Running Festival by UTMB 2026 in Swoope, United States. The race starts on September 19, 2026 at 07:00 AM.
The course climbs 1367 m+. With 26 m/km of climbing, this is a rolling, mostly runnable course. By gradient, 31% of the distance is uphill, 30% downhill and 39% flat. The longest climb runs 3.4 km at an average 5.8% grade (200 m of vertical). The longest descent runs 5.0 km at 11.0% (551 m of vertical). The steepest climb averages 29.7% over 0.3 km. The steepest descent drops at 20.8% over 0.5 km. Surface: 57% trail, 20% road, 13% smooth, and 10% extreme. Flat-equivalent effort: 62.7 FlatKM.
The course also passes close to Sand Spring Mountain (1137 m).
Poles bring little benefit here — only about 3.1 km of pole-friendly terrain.
Quad damage risk is low (index 15 of 100): a few descents worth noticing, none that decides the result.
Historically on race day, start temperatures range from 10°C to 18°C, around 18°C at the highest point; the chance of precipitation is about 33%. Heavy rain of 10.0 mm or more falls on about 8% of days around this date.
This page has the interactive elevation profile, gradient matrix, pacing and nutrition planner and weather climatology for Grindstone 50K.
Other distances of Grindstone Trail Running Festival by UTMB 2026·
Other editions of Grindstone 50K
Official websitegrindstone.utmb.world
