O'Brien 10 miler and 5k

Marine on Saint Croix, MN, USA
16 Sep, 2023 (Sat)


5 km, 10.4 mi, 50 km

About the event


O'Brien state park
15 mins north of Stillwater

16821 O'Brien Trail North
Marine on St. Croix, MN 55047

Marine On St Croix Weather and Forecast

William O'Brien State Park


50k course will run the 10 mile course 3 times. Course is mainly a wide grass trail with rolling hills. The hills will add up over the 3 loops.
Race starts at 8 am with a 8 hour time limit
Aid stations on each loop will be at mile 2.5, mile 5.5, mile 6.5 plus the end of each loop.

Entry Fee $50.00 till August 1st, $60.00 till September 4th. Race day is $70.00


There will be no refunds.

If COVID-19 and /or other conditions force the event to be be shut down and /or conditions are not safe the event will be made to a virtual event. If this happens race shirt and race number will be sent out with in one week of the completion of the event.


5k will be a single loop on grass trails.
$25.00 till September 4th.
Race day sign up is $30.00

Race day sign up is available

Race day sign is available for both events.
50k is $70.00
10 miler is $60.00, 5k is $30.00
If need be shirts will be mailed to you if not available at the race.
Check or cash please. No credit cards.


Some of the guidelines will be:
1. Mask to be worn till start of event.
2. Social distance while not running.
3. Respect of others and COVID-19 by not attending if sick or been in contact with someone who has COVID-19 in recent days before the event. 4. Tempature check in and COVID-19 waiver signed prior to start. 5. No group running. Honor social distance. 5. No Post race awards and gatherings.
More guidelines could come as the event becomes closer along with state and national information is passed down. For example race start could be staggered with a max amount of people in each stage. If COVID-19 conditions don’t improve and continue to increase, there’s a chance that the 2021 Min O’Brien in person trail races will have to be run virtually. If this happens, more details will be sent to all registered runners. All efforts will be made to wait as long as possible to make this decision.

10 Mile

Entry fee till August 1st is $40.00, $50.00 till September 4th, $60 on race day. >Race starts at 9am with a time limit of 2.5 hour time limit on finishing.

Course is mostly wide grass trails with plenty of rolling hills. From mile 1 till 2 you run along the St. Croix River under large pines with a gravel path.

Mile markers are on the course.

Aid station at Mile 2.75, 5.5 and 6.5. Aid station will have water and Gatorade only.

See link for course map with the state park trails listed.

See Link for mile markers.

See link for elevation

General Info

1. Parking included in entry fee.
2. No external music during the race. If you would like to have music please use headphones. Respect your fellow runner and campers at the park.
3. Awards will be top 3 over all male and female.
4. Aid station will be available for the 10 mile race only at mile 2.5 (water only), and mile 5.5 and 6.5 (water Gatorade, cookies, and other items)
5. Post race will have bottle water, Coke, cookies, granola bars, and bananas.


If dogs are are allowed is a frequent question.
All dogs must be on a 6 foot leash at all times. Park Rules
We love dogs however it has been our experience that dogs might react different when around strangers and might get over stimulated that could cause them to nip. With that being said you are responsible for your dogs and happy bring them along to enjoy the day with.

Races offered by this event

You have 24 weeks to prepare


16 Sep, 2023 (Sat)
50 km


16 Sep, 2023 (Sat)
5 km

10.4 Miler

16 Sep, 2023 (Sat)
10.4 mi

O'Brien 10 miler and 5k


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