O'Brien Trail Races
William O'Brien State Park, just off state highway MN-95, north of Marine on Saint Croix
Races start at the William O'Brien State Park Visitor Center, just inside the park and to the left.
Parking is at the Visitor Center lot. Please be considerate of other Center users.
COURSE: New in 2023 and 2024. You will likely run two 25k loops on new trails that have not been included in previous races.
Upcoming Races
Sep 26 2026
50 KM
Multiple Loop
9:00 Cutoff
3
Elevation Rating
Hilly, ~2500-7500 feet in 50 miles
2
Surface Rating
Mostly groomed trail or dirt roads
Results
50 KM
| Date | Finishers | Top Result (F) | Top Result (M) |
|---|---|---|---|
| 09/20/25 | 37 | 4:20:43 | 3:58:24 |
| 09/21/24 | 43 | 4:15:12 | 3:40:45 |
| 09/16/23 | 42 | 5:05:14 | 4:06:10 |
| 09/17/22 | 35 | 4:30:17 | 4:11:27 |
| 09/18/21 | 27 | 4:38:54 | 4:10:05 |
| 09/20/20 | 27 | 5:11:07 | 3:16:51 |
50 Miles
| Date | Finishers | Top Result (F) | Top Result (M) |
|---|---|---|---|
| 09/17/22 | 2 | 8:38:32 | 11:53:05 |