Trail ultramarathon · United States
18–20 September 2026 · Natural Chimneys Park, Virginia
21K: Sat, 19 September 2026
An Appalachian ultra weekend from Natural Chimneys with long climbs, ridge running, and established 100 mile and 100K demand.
Entry · 21K · 2026 edition
The organizer publishes the official results. Entry for the next edition is not on file yet. The organizer announces dates and entry rules; check their site before planning around a place.
From the organizer's page, checked 27 Sep 2026. TrailSplits does not know whether you have a place; the organizer is the final word.
Grindstone Trail Running Festival by UTMB is a trail ultramarathon scheduled for 18–20 September 2026 in Natural Chimneys Park, Virginia, United States. TrailSplits currently includes 4 mapped courses for this event, with course maps, elevation profiles, weather context, and pacing tools for the uploaded GPX data.
How to get a place: 2027 registration 'opens soon' with no date yet. The 2026 edition was direct registration until 13 September 2026 or sell-out, plus onsite expo entries; no lottery was described. Organizer's page, checked Sunday 27 September 2026.
TrailSplits is a free, independent route & pacing companion — not the official race. Visit the official Grindstone Trail Running Festival by UTMB site →
The organizer lists 21K at 21 km and +500 m for 2027; the course file mapped here (the organizer's 2025 file) measures 21.7 km. Small differences come from how each figure was measured; plans and pacing here use the mapped file. Organizer's race list, checked Wednesday 30 September 2026.
Finishing 21K earns 1 Running Stone (20K category) toward the UTMB World Series Finals lottery. How Running Stones work.
Racing more than once next year? Add 21K to a season and see whether your races work together.
Inspect the official course track on a topographic map, through its elevation profile, or in 3D.
› running direction two lines: out and back on the same path kilometres
Selected distance
Vert-focused blueprint with route-finder links into the Planner.
Prepare and return
Keep this course, its training plan, calendar and future course updates together in your private My Races page. Saving does not publish your workouts, pace or progress.
Race route lab
Open the official course in Planner, then choose a nearby start point to build a shorter loop that matches the course demand. This course averages about 23.8 m climb per km.
Sat, 19 September 2026
Send to your watch
Get the official course as a clean GPX or a Garmin TCX course, with step-by-step instructions to load it onto a Garmin, COROS, Suunto, Wahoo, or Komoot — free, no account needed.
Compare your training
See how faithfully your rehearsal route matches the real race. The official course for 21K loads as Route A — upload your training route to compare distance, elevation gain, estimated time, and how much of the course you actually cover.
Course analysis
See the 21K course broken into its major climbs and descents in order — length, gain, average grade, and steepness — so you know where the crux is and how to pace and fuel it.
Grindstone Trail Running Festival by UTMB 2026 races run 18–20 September 2026 in Natural Chimneys Park, Virginia; the 21K is on Sat, 19 September 2026. Check the official race site for registration deadlines and final details.
4 distances (21–167.4 km). The longest course is 167.4 km with about 6,400 m of vertical gain — a demanding mountain course.
The 100M course has a 36-hour cut-off, an average of 12.9 min/km to finish in time. TrailSplits' cut-off pacer shows the buffer at each aid station.
Yes. TrailSplits gives you the course map, an interactive elevation profile, a 3D flyover and a downloadable GPX for every mapped distance — free and with no sign-up.
Each distance has a free, course-specific 16-week training plan built around its distance, vertical gain and cut-offs, plus a pace and cut-off calculator.
No. TrailSplits is a free, independent route and pacing companion. For registration and official rules, visit https://grindstone.utmb.world/.
Load the GPX directly into TrailSplits for surface analysis and terrain intel.