Grindstone by UTMB - 100 Mile - Elevation Profile, Aid Stations and Cutoffs
- Natural Chimneys Park, Virginia, USA
- 167.4 km
- 6,400 m D+
- 15 aid stations
Map, checkpoints and cutoffs Map · checkpoints · forecast opens Sep 8 Race-day forecast is live
Race-day conditions
Weather, daylight and your arrival time at all 17 checkpoints, set to the 18:00 start.
- Start
- 18:00
- Daylight at the start
- 06:58-19:22
- Aid stations
- 15
Course profile
Natural Chimneys Park, Virginia, USA
- Distance
- 167.4 km Finishes 2 m lower than it starts
- Elevation
- +6,400 m -6,402 m About 38 m of climb per km
Next edition Est. Fri 17 Sept 2027
Our estimate for Fri 17 Sept 2027. The organiser has not announced the date for this race yet.
- Start
- Sunset 1h23 after the start
- Sunrise 12h60 after the start
- Winner ~21h48 21h48 after the start
- Mid-pack finish UTMB Index 500 32h06 after the start
- Cutoff 36h after the start
A mid-pack runner spends about 18h22 in the dark.
Grindstone by UTMB - 100 Mile is a 167.4 km (about 104 miles) ultra-trail with around 6,400 m of elevation gain, starting in Natural Chimneys Park, Virginia, USA. The overall cutoff is 36 hours. That is 38 m of climbing per kilometre.
The biggest climb between checkpoints gains around 920 m from Wolf Ridge (km 18.3) to Reddish Knob (km 32.8). The steepest sustained section on the elevation profile averages about 17% over roughly 2.7 km around km 134. Crew access is allowed at North River Gap 1 (52.1 km), Dowells Draft 1 (73.4 km), Dowells Draft 2 (115.7 km), Camp Todd (132.1 km) and North River Gap 2 (147.7 km). Drop bags are available at North River Gap 1, Dowells Draft 1, Dowells Draft 2, Camp Todd and North River Gap 2.
Data is approximate and courses change between editions - always verify against the official race guide.
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Course math
Four numbers worked out from this course's distance, elevation and checkpoints.
TrailMath effort-km
263 effort-km
About 32 h for a mid-pack finisher (index 500). Not a pacing guarantee.
Distance + gain ÷ 100 + loss ÷ 200, beside ITRA's gain-only km-effort. Model TM1.0.
How TrailMath works →UTMB Index category
100M
231 km-effort (distance + gain ÷ 100). Calculated from the course figures, not an official classification.
Estimate your UTMB Index →Biggest climb section
+920 m
Wolf Ridge → Reddish Knob · km 18.3–32.8
The largest gain between two checkpoints, not one continuous climb.
Wolf Ridge cutoff: Fri 21:30
Plan against barriers →Biggest descent section
−1,040 m
Camp Todd → North River Gap 2 · km 132.1–147.7
The largest loss between two checkpoints. ITRA's km-effort ignores descent; TrailMath counts it: 263 km-effort.
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~49 weeks · peak ~8 h/week · 5 run + 2 strength days
For a 167.4 km race, aim for about 12 h/week at peak. Set your availability to 14 h/week in the app for the headroom to build there gradually.
Typical structure for your volume - your live plan adjusts sessions inside each week.
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Aid stations and checkpoints
| Checkpoint | Km | Cumulative gain (m) | Cumulative loss (m) | Cutoff |
|---|---|---|---|---|
| Start - Natural Chimneys Services not published | 0 | 0 | 0 | - |
| Lick Run 1 | 9.2 | 230 | 100 | - |
| Wolf Ridge | 18.3 | 530 | 380 | Fri 21:30 |
| Reddish Knob | 32.8 | 1,450 | 560 | Sat 00:30 |
| Little Bald Knob | 39.3 | 1,600 | 770 | - |
| North River Gap 1 Crew Drop bag | 52.1 | 1,920 | 1,780 | Sat 04:00 |
| Lookout Mountain | 61.3 | 2,400 | 2,000 | - |
| Dowells Draft 1 Crew Drop bag | 73.4 | 2,740 | 2,510 | Sat 09:00 |
| Dry Branch Gap 1 | 84.7 | 3,410 | 3,000 | Sat 11:00 |
| Cold Springs | 95.6 | 4,030 | 3,710 | - |
| Dry Branch Gap 2 | 104.4 | 4,270 | 3,910 | Sat 15:30 |
| Dowells Draft 2 Crew Drop bag | 115.7 | 4,760 | 4,560 | Sat 18:00 |
| Magic Moss | 124.1 | 5,100 | 4,800 | Sat 20:00 |
| Camp Todd Crew Drop bag | 132.1 | 5,180 | 4,870 | Sat 21:30 |
| North River Gap 2 Crew Drop bag | 147.7 | 6,000 | 5,910 | Sun 01:45 |
| Lick Run 2 | 160.1 | 6,350 | 6,220 | - |
| Natural Chimneys (Finish) Crew Drop bag | 167.4 | 6,400 | 6,402 | Sun 06:00 |
Data is approximate and courses change between editions - always verify against the official race guide. Source: official race guide, verified July 17, 2026 - Official race website
FAQ
How much elevation gain does Grindstone by UTMB - 100 Mile have?
Grindstone by UTMB - 100 Mile has around 6,400 m of cumulative elevation gain and 6,402 m of loss over 167.4 km.
What is the cutoff time for Grindstone by UTMB - 100 Mile?
The overall Grindstone by UTMB - 100 Mile cutoff is 36 hours, with intermediate time barriers at major checkpoints. Winning times are typically around 22 hours.
How long is Grindstone by UTMB - 100 Mile?
Grindstone by UTMB - 100 Mile covers approximately 167.4 km (about 104 miles), starting in Natural Chimneys Park, Virginia, USA.
How many aid stations does Grindstone by UTMB - 100 Mile have and which allow crew?
The checkpoint table lists 15 major aid points between the start and the finish. Crew access is allowed at North River Gap 1 (52.1 km), Dowells Draft 1 (73.4 km), Dowells Draft 2 (115.7 km), Camp Todd (132.1 km) and North River Gap 2 (147.7 km). Drop bags are available at North River Gap 1, Dowells Draft 1, Dowells Draft 2, Camp Todd and North River Gap 2.
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