Grindstone Trail Running Festival - 100M 2025
The forecast arrives five days before the start.
Here you'll find the elevation profile and an estimated finish time based on your UTMB Index.
What's your time based on your UTMB?
Times estimated by the RAVIT model, learned from real ultra-trail finish times. Enter your UTMB Index (utmb.world) to get a personalized estimate.
Predicted race time based on your UTMB Index® · smoothed times achieved by runners at your level in past editions
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Cut-off times and crew - Grindstone Trail Running Festival - 100M · 2025
| Aid station | Cum. km | Cum. D+ | Seg. km | Seg. D+ | Seg. D- | Crew | Cut-off | Access |
|---|---|---|---|---|---|---|---|---|
| Lick Run - 1 | 9.2 | 0 m | 9.2 | 194 m | 69 m | — | — | — |
| Wolf Ridge | 18.7 | 0 m | 9.4 | 299 m | 282 m | — | Fri 09:30 PM | — |
| Reddish Knob | 33.0 | 0 m | 14.4 | 917 m | 172 m | — | Sat 12:30 AM | — |
| Little Bald Knob | 39.4 | 0 m | 6.4 | 127 m | 212 m | — | — | — |
| North River Gap - 1 | 53.2 | 0 m | 13.8 | 328 m | 1,051 m | — | Sat 04:00 AM | — |
| Dowells Draft - 1 | 74.7 | 0 m | 21.4 | 825 m | 710 m | — | Fri 09:00 AM | — |
| Dry Branch Gap - 1 | 85.8 | 0 m | 11.1 | 648 m | 466 m | — | Sat 11:00 AM | — |
| Cold Springs | 96.7 | 0 m | 10.9 | 622 m | 680 m | — | — | — |
| Dry Branch Gap - 2 | 105.6 | 0 m | 9.0 | 248 m | 190 m | — | Sat 03:30 PM | — |
| Dowells Draft - 2 | 116.7 | 0 m | 11.0 | 467 m | 649 m | — | Sat 06:00 PM | — |
| Magic Moss | 125.3 | 0 m | 8.7 | 347 m | 244 m | — | Sat 08:00 PM | — |
| Camp Todd | 133.4 | 0 m | 8.1 | 87 m | 75 m | — | Sat 09:30 PM | — |
| North River Gap - 2 | 149.3 | 0 m | 15.8 | 837 m | 1,067 m | — | Sun 01:45 AM | — |
| Lick Run - 2 | 161.8 | 0 m | 12.5 | 353 m | 308 m | — | — | — |
| Natural Chimneys | 168.9 | 0 m | 7.1 | 30 m | 154 m | — | Sun 06:00 AM | — |
Data from the official race rules, checked for every edition. The race rules prevail. Positions are interpolated along the GPX track and are a guide, not official course marking.
What you'll find at each aid station
Aid station contents not documented.
La feuille de ton assistance pour Grindstone Trail Running Festival - 100M · 2025
Les règles d'assistance de cette course ne sont pas encore connues : tu marqueras tes rendez-vous toi-même.
Recto, verso et planche d'étiquettes, en PDF : l'exemple d'une coureuse de l'UTMB.
Elevation profile
The course and its aid stations
Grindstone Trail Running Festival - 100M: times, aid-station stops and fuelling needs by UTMB® Index
Between a UTMB® Index of 500 and 800, the estimated finish time on this race runs from 33h52 to 20h51. These times include aid-station stops: they come from real durations between two timing points, and this race's timing does not measure stops separately.
SourceBelow a UTMB® Index of roughly 440, the overall cut-off of 35h59 is no longer reachable at the estimated pace.
| UTMB® Index | Estimated time | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|
| 500 | 33h52 | 16.9 | 2,032 g | 23.7 L | 16,933 mg | +2h07 |
| 550 | 30h21 | 13.4 | 1,821 g | 21.2 L | 15,175 mg | +5h38 |
| 600 | 28h51 | 11.9 | 1,731 g | 20.2 L | 14,425 mg | +7h08 |
| 650 | 26h51 | 10 | 1,611 g | 18.8 L | 13,425 mg | +9h08 |
| 700 | 24h18 | 10 | 1,458 g | 17 L | 12,150 mg | +11h41 |
| 750 | 22h31 | 10 | 1,351 g | 15.8 L | 11,258 mg | +13h28 |
| 800 | 20h51 | 10 | 1,251 g | 14.6 L | 10,425 mg | +15h08 |
Figures based on 60 g of carbohydrate, 700 mL of fluid and 500 mg of sodium per hour, "average" preparation and mild conditions (15–25 °C). Above 25 °C, count on roughly 900 mL/h and 700 mg/h. Carbohydrate intake is trained: 60 g/h is a floor, 90 g/h assumes a glucose-fructose blend and a gut used to it.
Measured on the 2025 edition: the field checkpoint by checkpoint
194 starters, 43.8% DNF rate, 16 timed checkpoints.
| Segment | km | Median | Middle half | Measured | Median passage | Still ranked |
|---|---|---|---|---|---|---|
| Natural Chimneys → Lick Run - 1 | 9.2 | 1 h 02 | 53 min – 1 h 07 | 194 | 1 h 00 | 194 |
| Lick Run - 1 → Wolf Ridge | 18.7 | 1 h 20 | 1 h 12 – 1 h 26 | 191 | 2 h 20 | 192 |
| Wolf Ridge → Reddish Knob | 33 | 2 h 37 | 2 h 21 – 2 h 47 | 188 | 4 h 54 | 189 |
| Reddish Knob → Little Bald Knob | 39.4 | — | — – — | 0 | — | 164 |
| Little Bald Knob → North River Gap - 1 | 53.2 | — | — – — | 0 | 8 h 19 | 164 |
| North River Gap - 1 → Lookout Mountain | 62.5 | — | — – — | 0 | — | 151 |
| Lookout Mountain → Dowells Draft - 1 | 74.7 | — | — – — | 0 | 12 h 46 | 151 |
| Dowells Draft - 1 → Dry Branch Gap - 1 | 85.8 | 1 h 52 | 1 h 43 – 2 h 01 | 146 | 14 h 35 | 146 |
| Dry Branch Gap - 1 → Cold Springs | 96.7 | — | — – — | 0 | — | 130 |
| Cold Springs → Dry Branch Gap - 2 | 105.6 | — | — – — | 0 | 18 h 49 | 130 |
| Dry Branch Gap - 2 → Dowells Draft - 2 | 116.7 | 1 h 49 | 1 h 38 – 1 h 59 | 128 | 20 h 32 | 128 |
| Dowells Draft - 2 → Magic Moss | 125.3 | 2 h 17 | 1 h 55 – 2 h 30 | 74 | 24 h 05 | 120 |
| Magic Moss → Camp Todd | 133.4 | 1 h 30 | 1 h 20 – 1 h 46 | 67 | 24 h 31 | 116 |
| Camp Todd → North River Gap - 2 | 149.3 | 3 h 56 | 3 h 31 – 4 h 23 | 104 | 28 h 16 | 112 |
| North River Gap - 2 → Lick Run - 2 | 161.8 | 2 h 43 | 2 h 15 – 3 h 01 | 106 | 30 h 56 | 110 |
| Lick Run - 2 → Natural Chimneys | 168.9 | 1 h 07 | 52 min – 1 h 19 | 106 | 32 h 10 | 109 |
“Median passage” is elapsed time from the start, not a clock time: the clock time depends on the edition.
Where runners drop out. Reddish Knob (25) · Dry Branch Gap - 1 (16) · North River Gap - 1 (13) out of 85 total DNFs.
RAVIT record from the official timing of the 2025 edition, data from September 16, 2026.
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Grindstone Trail Running Festival - 100M over the years
Sources and method
- Time projection — times by UTMB Index are taken from the actual splits of runners in each level band on previous editions of this race, aid station stops included. No formula is used as long as these results exist.
- Trail nutrition — hourly targets for carbohydrate, fluid and sodium follow the commonly accepted ultra-endurance guidance. La Clinique du Coureur — Fuelling in trail running
- Course, aid stations and cut-offs — taken from the event's official rules, which prevail in case of any discrepancy. Official site — Grindstone Trail Running Festival - 100M
Weather for Grindstone Trail Running Festival - 100M
The weather for Grindstone Trail Running Festival - 100M will appear here as soon as the forecast models reach that date, around five days before the start: feels-like temperature, rain, snow, wind and storms, section by section and at your passage time.
Detailed weather for Grindstone Trail Running Festival - 100M, hour by hour on the courseFrequently asked questions
How many checkpoints?
Grindstone Trail Running Festival - 100M has 15 checkpoints: 15 checkpoints with undocumented contents. Details are in the two tables above.
What distance and elevation gain?
Grindstone Trail Running Festival - 100M is 169 km long with 6329 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 28h51 for Grindstone Trail Running Festival - 100M.
What's the weather forecast?
The weather for Grindstone Trail Running Festival - 100M will be published on this page around five days before the start, once the forecast models reach the race date. It will be detailed section by section: feels-like temperature, rain, snow, wind and storms.
Want to stack the odds in your favor for Grindstone Trail Running Festival - 100M?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
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