Stone Mill 50M
The Stone Mill 50 Mile is a 50 mile trail run on the Seneca Greenway and Muddy Branch trails in Montgomery County Md. The course traverses forested, rolling terrain. The course is primarily on single track dirt. There are small stream crossings. Most of the course drains well, but parts can be muddy in wet weather.
Upcoming Races
Nov 7 2026
50 Miles
4,000
4,000
ft.
Lollipop
10 Aid
Stations
13:00 Cutoff
3
Elevation Rating
Hilly, ~2500-7500 feet in 50 miles
3
Surface Rating
Some rocks, root, and/or ruts
Results
50 Miles
| Date | Finishers | Top Result (F) | Top Result (M) |
|---|---|---|---|
| 11/08/25 | 222 | 8:45:47 | 6:58:52 |
| 11/09/24 | 194 | 8:20:47 | 6:56:21 |
| 11/11/23 | 171 | 8:45:02 | 7:05:38 |
| 11/12/22 | 175 | 8:29:59 | 7:21:30 |
| 11/13/21 | 220 | 8:10:44 | 6:56:28 |
| 11/14/20 | 167 | 8:24:47 | 6:41:23 |
| 11/09/19 | 250 | 8:35:57 | 6:51:42 |
| 11/17/18 | 244 | 9:03:14 | 7:15:00 |
| 11/11/17 | 252 | 8:25:02 | 7:21:41 |
| 11/12/16 | 211 | 8:57:15 | 7:19:13 |
| 11/14/15 | 282 | 8:05:30 | 7:04:13 |
| 11/14/14 | 261 | 8:25:41 | 6:49:16 |
| 11/16/13 | 251 | 7:46:19 | 7:06:35 |
| 11/17/12 | 259 | 8:16:31 | 7:25:13 |
| 11/19/11 | 178 | 9:41:26 | 8:02:22 |
| 11/20/10 | 117 | 8:38:32 | 7:34:15 |
56 Miles
| Date | Finishers | Top Result (F) | Top Result (M) |
|---|---|---|---|
| 11/20/10 | 6 | 8:38:24 |