William O'Brien State Park
William O'Brien State Park protects a scenic stretch of the St. Croix River with wooded bluffs, prairie, wetlands, and river access. Visitors come for camping, paddling, birdwatching, and year-round outdoor recreation in a quiet setting near the Twin Cities.
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Visiting with Dogs
Dogs allowed in park and campgrounds; must be leashed no longer than 6 feet. Not allowed in buildings or swim areas.
Visitor Tips & Reviews
What Visitors Say
Scenic river views, peaceful trails, great camping, and abundant wildlife make William O'Brien State Park a favorite for hiking, paddling, fishing, and relaxing family outings.
Tips from Visitors
- Check trail conditions before hiking, especially after rain or snow.
- Bring insect repellent for mosquitoes and ticks in warmer months.
- Pack water and snacks; amenities may be limited on trails.
- Watch for wildlife and keep a safe distance at all times.
- Reserve campsites early during weekends and peak summer seasons.
Best Time to Visit
The best time to visit William O'Brien State Park is late spring through early fall, when the St. Croix River is ideal for paddling and the woods are lush and green. Fall brings colorful foliage and excellent bird migration viewing.
Amenities
Nearby Attractions
Explore these attractions near William O'Brien State Park:
- William O'Brien State Park Visitor CenterThe park's main hub for maps, exhibits, and seasonal information about recreation and wildlife.0.2 miles away
- St. Croix National Scenic RiverwayA protected river corridor offering paddling, fishing, and scenic views along one of the region's most popular waterways.0.5 miles away
- Marine Mill Historic SiteA historic site in Marine on St. Croix that interprets the area's early lumber and milling history.4 miles away
Things to Do at William O'Brien State Park
Camping at William O'Brien State Park
Tent and RV camping with electric sites, showers, restrooms, fire rings, picnic tables; reservations recommended; seasonal availability.
Hiking Trails
William O'Brien State Park offers pleasant day hiking with a mix of wooded trails, prairie openings, and scenic views along the St. Croix River. Reviews often mention well-kept paths, moderate terrain, and a peaceful atmosphere, making it a good choice for casual hikers and families. Trails are generally easy to follow, with enough variety to keep a short visit interesting.
River Terrace Trail
EasyA scenic loop along the St. Croix River bluffs with wooded sections, river views, and access to picnic and campground areas.
Kingfisher Trail
EasyA short, family-friendly trail through oak woodland and prairie with opportunities for birdwatching and quiet river-adjacent scenery.
Prairie Trail
ModerateA longer hike across restored prairie and mixed forest, offering open views, seasonal wildflowers, and a good workout with gentle hills.
O'Brien Trail
ModerateOne of the park's best all-around hikes, combining forest, prairie, and river valley landscapes with varied terrain and multiple scenic overlooks.
Directions
From Marine on St. Croix, follow County Road 4 north, then turn onto O'Brien Trail N and continue to the park entrance. From the Twin Cities, take I-35 to Highway 97 east, then local roads north to Marine on St. Croix.
Contact & Info
Frequently Asked Questions
What are the most popular things to do at William O'Brien State Park?
Visitors commonly come for hiking, camping, fishing, canoeing/kayaking, and wildlife viewing. The St. Croix River and the park’s prairie and forest trails are especially popular in reviews.
Is William O'Brien State Park good for families with kids?
Yes. Many visitors say it’s a good family park because the trails are manageable, the river area is scenic, and there’s plenty of space to explore. Families often enjoy picnicking, beach time, and easy nature walks.
Can you swim at William O'Brien State Park?
Swimming is typically possible in the park’s designated beach area when conditions allow. Visitors often mention that water levels and river conditions can vary, so it’s best to check current safety information before swimming.
Are the trails at William O'Brien State Park easy or difficult?
The park has a mix of easy and moderate trails. Reviewers often describe them as scenic and well-maintained, with some gentle routes and some longer hikes. Trail conditions can change with weather and season.
Is camping at William O'Brien State Park worth it?
Many campers say yes, especially for the quiet setting and river access. The campground is often described as clean and well-kept. Some visitors recommend booking early during peak season because sites can fill up quickly.
What wildlife might I see at William O'Brien State Park?
Visitors often report seeing birds, deer, squirrels, and other small wildlife. Birdwatchers especially like the park. Wildlife sightings vary by season and time of day, so early morning and evening are often the best times to look.
Don’t Forget the Essentials
Essential camping & hiking gear we recommend to make your park trip easier and more comfortable.
View Gear Checklist →