O'Brien Trail Races

O'Brien Trail Races

Register Saturday, Sep 26, 2026

Location: William O'Brien State Park, 16821 O'Brien Trail North, Marine on St Croix, MN

Races start at the William O'Brien State Park Visitor Center.

Races Offered:

• 50K
• 25K
• 10K
• 5K

Start Times:

• 50K: 8:00 a.m.
• 25K: 9:00 a.m.
• 10K: 9:05 a.m.
• 5K: 9:10 a.m.

Course Details:

• 50K: Two 25k loops using the upper section, south section of the park and Jackson Meadows. Cut off: 9 hours (5pm). Must start 2nd loop at noon.
• 25K: Course tbd. Cut off: 5 hours.
• 5K & 10K: Wide grass trails with one large hill and a flat finish line. Cut off: 2 hours. (10k does the 5k twice).

Registration Information:

Online registration closes: September 21st, 2026.

Race day registration available for $75 (50K/25K) or $10 (5K/10K).

Entry Fees:

• 50K: $40 (early bird), $55 (after Dec 01), $65 (Aug 1st till Sept 21st), $75 (race day).
• 25K: $30 (early bird), $45 (after Dec 01), $55 (Aug 1st till Sept 22nd), $65 (race day).
• 10K: $10.
• 5K: $5.

General Info:

• No external music during the race; headphones allowed.
• Aid stations will have water, Gatorade, cookies, etc.
• Post-race food includes water, soda, cookies, chips, etc.
• Packet pickup on race morning only.
• No refunds. Entries may not be transferred or deferred.
• If COVID-19 or other conditions force event shutdown, races will become virtual.