O'brien Trail Races
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O'Brien Trail Races : September 26, 2026
The event takes place at William O'Brien State Park in Marine on Saint Croix, Minnesota. It is organized by True North Adventures and includes multiple trail race distances held within the park and nearby Jackson Meadows.
- 50K
- 25K
- 10K
- 5K
The 50K is run as two 25K loops using the park's upper and south sections and Jackson Meadows. Aid stations are provided on the longer courses, with four aid stations per 25K loop. Drop bags are allowed at the start/finish area only. The 25K also uses trail sections in the park, includes multiple aid stations, and has a time limit for completion.
The 10K and 5K are held on wide grass trails with one large hill and a flat finish; the 10K completes the 5K loop twice. These shorter races do not have aid stations, awards, or included race shirts; all finishers receive a full-color 8.5 x 11 print of the event logo.
General race logistics include packet pickup on race morning only, parking at the Visitor Center lot, and bathrooms inside the Visitor Center. External music is not allowed without headphones. Typical aid station fare and post-race food items are water, sports drink, cookies, and snacks.
No refunds are offered and entries may not be transferred, deferred, or applied to another event. If the event is converted to virtual, race shirts and numbers will be mailed after the event. Visit the organization's website for the most recent information.
