O'Brien Trail Races

SEP

25

2027

Trail races at William O'Brien State Park on Sep 25, 2027 offering 50K, 25k, 10K and 5k with aid stations, finish cutoffs, and a full-color finisher print.

Sat 25 Sep 2027

Marine on Saint Croix, Minnesota

Website

50 kilometers 25 kilometers 10 kilometers 5 kilometers

Always double-check with the organizer's website! This page may contain affiliate links.

O'Brien Trail Races - William O'Brien State Park, Sep 25, 2027

O'Brien Trail Races take place at William O'Brien State Park in Marine on St Croix, Minnesota on September 25, 2027. The event is organized by True North Adventures and offers multiple trail distances.

Distances

50K two 25k loops using the upper section, south section of the park, and Jackson Meadows.
25k
10K repeats the 5k loop twice on wide grass trails.
5k wide grass trails with one large hill and a flat finish.

Course and support details include four aid stations for the 25k and 50k, drop bags at the start/finish area only, and no aid stations for the 5k and 10k. The 50K uses two 25k loops; the race has an overall finish cutoff of nine hours and a midway start cutoff that effectively limits the first 25k to roughly four hours. The 25k cutoff is five hours. The 5k and 10k have a two-hour finish cutoff.

Logistics and services: packet pickup is race morning only; bathrooms are available inside the Visitor Center at the start/finish area; post-race food includes bottled water, soda, cookies, gummies, chips, salted nut rolls, and pickles. All finishers receive a full color 8.5 x 11 print of the current year logo.

Entry fees vary by distance and registration date; race day registration fees are listed for each distance. There are no refunds, no transfers, and no deferrals. If the event is converted to a virtual format due to public-health restrictions, shirts and race numbers will be mailed within one week of the event. Visit the organization's website for the most recent information.