Grindstone Trail Running Festival
Grindstone Trail Running Festival – 50K
Natural Chimneys Park
Race guide
Updated 18 July 2026
The Grindstone Trail Running Festival 50K is a 50 km mountain trail race that starts and finishes at Natural Chimneys Park, Virginia. With 1339 m of vertical gain and a high point of 1145 m, it packs classic Blue Ridge climbing into a single hard day, threading up onto forested ridgelines before dropping back to the valley floor. Starting and finishing at 409 m, the loop is bookended by the same low ground and centred on a big middle section that pushes up toward its 1145 m ceiling. It is long enough to demand real ultra discipline yet short enough to run assertively, making it a strong step up for road-marathoners moving to trail or a fast day out for seasoned mountain runners. The single hard 16:00 finish cut-off gives you a clear, generous time budget to work against.
The Course and Terrain
The 50K is an out-and-loop from Natural Chimneys Park that keeps returning to familiar ground: you pass Lick Run early at 9.2 km (533 m) and again late at 45.2 km (534 m) on the way home, which makes the aid schedule easy to rehearse. Between those two Lick Run visits the course climbs onto the higher terrain around Wolf Ridge at 18.5 km (551 m) and Sand Spring at 34.2 km (594 m), the two checkpoints that anchor the middle of the race. The start and finish both sit at 409 m, so every metre you climb out of the park must be given back before you are done. With 1339 m of gain spread across 50 km the average grade is moderate rather than brutal, but the profile is lumpy: expect rolling forest doubletrack and singletrack with repeated short-to-medium climbs rather than one sustained ascent. The named high point of 1145 m marks the top of the range you spend the mid-race hours moving through.
Where the Race Is Won and Lost
The decisive third of this race is the stretch from Wolf Ridge (18.5 km, 551 m) through Sand Spring (34.2 km, 594 m). This is where you gain and hold the high ground near the 1145 m ceiling, and where a race run too hard in the opening 18 km will start to unravel. Reaching Sand Spring with your legs intact is the single best predictor of a strong finish. The closing move is the long descent off the high country back toward Lick Run 2 at 45.2 km (534 m) and then down to the 409 m finish. That final drop is where fresh quads pay off and trashed ones get punished, because you lose well over 100 m of net elevation in the last few kilometres on tired legs. Run the middle climbs conservatively so you can actually race the runnable descent home rather than survive it.
Pacing and Fueling to the Cut-offs
There are three time gates to manage: Wolf Ridge at 18.5 km closes Sat 10:00, Sand Spring at 34.2 km closes Sat 12:45, and the finish at 50 km closes Sat 16:00. The gaps between them are comfortable for a steady runner, but the Sand Spring cut-off is the one to respect because it sits just past the toughest, highest section of the course. Build a small buffer early on the runnable lower ground so a slow patch on the climbs does not put the mid-race gate in doubt. Aid is well spaced for a 50 km day: Lick Run at 9.2 km, Wolf Ridge at 18.5 km, Sand Spring at 34.2 km and Lick Run again at 45.2 km give you regular refuel points, with the longest carry being the roughly 16 km from Wolf Ridge to Sand Spring across the high middle. Fuel and hydrate through that gap deliberately, since it combines the most climbing with the widest spacing. From Sand Spring onward the checkpoints come more frequently as you descend, so you can run lighter into the finish.
Conditions to Expect
This is a Blue Ridge mountain course, so plan for cooler, potentially damp air up on the ridge around the 1145 m high point and warmer, more humid conditions down at the 409 m start and finish. The elevation swing of over 700 m between valley and high ground means the temperature and exposure you meet at Wolf Ridge and Sand Spring can differ noticeably from what you felt leaving Natural Chimneys Park. On forested Appalachian singletrack, footing is the recurring challenge: expect roots, rock and leaf litter that can hide the trail surface, especially on the descents back toward Lick Run and the finish. Because the start and finish share the same park at 409 m, crew access is straightforward at both ends of your day. Prepare for the classic mountain-trail mix of runnable climbs, technical descents and changeable temperatures rather than any single dominant hazard.
Race Grindstone Trail Running Festival – 50K with Crux
Get the strategy, fuelling and crew plan dialled for this exact course — built from the real route, climbs and cut-offs. Your first race is free.
Plan this race — freeCourse profile
Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-17) · official source
0 km · 409 m · —
9.2 km · 533 m · —
18.5 km · 551 m · Sat 10:00
34.2 km · 594 m · Sat 12:45
45.2 km · 534 m · —
50 km · 409 m · Sat 16:00
More races
More UTMB World Series
More in United States
Similar distance (50–100 km)
Racing Grindstone Trail Running Festival – 50K?
Get a complete race strategy — pacing, fuelling, crew plan and the crux moments — built on this exact course.
Plan your race in Crux →Strava is your training. Crux is your races.