William O'Brien State Park
Also known as O'Brien State Park
- Status
- Open (per official listing)Daily 8 a.m. – 10 p.m.
- Entrance fee
- Statewide rule — see below
- Day-use reservations
- None mentioned
- Dogs
- Dogs allowed6-ft leash
- Camping
- YesAlso cabins, glamping or camper cabins
- Official site
- dnr.state.mn.us(651) 539-4980
Official page last checked Oct 29, 2026. Details last changed Oct 29, 2026. How we keep this current
Current alerts 2
Partial closure Season Close October 19th, 2026The dump station, shower facilities, flushable toilets and jug fillers will be available through Sunday, October 18th. Beginning October 19th,… (more)
The dump station, shower facilities, flushable toilets and jug fillers will be available through Sunday, October 18th. Beginning October 19th, seasonal closures will begin including: • Dump station • Shower and restroom facilities in the campgrounds • Jug fillers throughout the campgrounds and Day Use Area • Flushable toilets in the Day Use Area • Riverway Campground, Wedge Hill and Riverside Group Camps, walk-in sites, and some loops in the Savanna Campground Vault toilets will be available in the Day Use Area and Savanna Campground. Camper or RV tanks can be filled with potable water behind the Ranger Station. Flushable toilets will be available at the Visitor Center during park hours. The public water access on the St. Croix is currently closed due to low water levels and high sediment. Small, non-motorized watercraft are still able to launch in the current conditions. Motorized watercraft should use alternate launches, such as Osceola or Somerset landing.
Posted by the park. Official alert
Partial closure Lake Alice reconstruction projectIn early August 2025, a mechanical failure of Lake Alice's water control structure resulted in a drawdown of the lake. After evaluating options for… (more)
In early August 2025, a mechanical failure of Lake Alice's water control structure resulted in a drawdown of the lake. After evaluating options for the site, DNR staff has a plan to replace the lake's water control structure and dredge the park's public water access. The following areas are closed to the public through construction completion (estimated fall 2027): Lake Alice beach, Lake Alice fishing pier and accessible canoe/kayak launch on Lake Alice. For construction updates, visit the Lake Alice construction page. Updated September 22nd, 2026
Posted by the park. Official alert
Overview
Covering about 1,723 acres, William O'Brien State Park lies in Washington County, about 10 miles east of Forest Lake.
Popular activities here are cross-country skiing, horseback riding, winter sports, swimming, and boating. Its trail network totals roughly 12 miles, according to the park. Facilities for water recreation include a swimming beach and a fishing pier. For overnight stays there are 3 camping areas (RV sites with electric hookups, tent sites, group camping, and showers). If you'd rather not camp, the park offers cabins and camper cabins or similar shelters.
Hours
Park, gate, office and facility hours are listed separately because they often differ. Alerts above override normal hours.
| Facility | Days | Hours | Season |
|---|---|---|---|
| Park | Daily | 8 a.m. – 10 p.m. | — |
| Other — Summer 2026 | Mon–Thu | 9 a.m. – 3:30 p.m. | — |
| Fri | 9 a.m. – 9 p.m. | — | |
| Sat | 9 a.m. – 7 p.m. | — | |
| Sun | 9 a.m. – 5 p.m. | — | |
| Park | Rentals: Canoe and kayak rentals closed for the season and will be available in May 2026. Drinking water: Water is available at the Ranger Station and Visitor Center. Bathrooms: Modern bathroom facilities are available from late April through mid-October. Vault toilets are available throughout the park. The vault toilets in the two campgrounds and the picnic grounds are available seasonally when the modern facilities are not open. Water: Water will be off beginning October 19th. During the off-season tanks can be filled with potable water behind the Ranger Station. Vault toilets will be open throughout the campground and day use area. Flushable toilets and potable water is available at the Visitor Center. Dump station: The dump station is available late April through mid-October for campers only. Campgrounds: The Savanna Campground is open year-round. The Riverway Campground is open mid-April - October. Electric sites: 30 amp max. in the Riverway Campground, 50 amp max. in the Savanna Campground Trails: The park has 12 miles of hiking trails. Dogs are permitted, but must be on a leash no longer than 6 feet and attended at all times. Showers: Shower buildings are available from late April through mid-October. Programs: Find park interpretive programming and events. | ||
Official wording
Daily from 8 a.m. until 10 p.m.
Summer 2026: Hours may vary due to staff availability and on holidays. Monday through Thursday: 9:00am to 3:30pm Friday: 9:00am to 9:00pm Saturday: 9:00am to 7:00pm Sunday: 9:00am to 5:00pm
The Savanna Campground is open year-round. The Riverway Campground is open mid-April - October.
Rentals: Canoe and kayak rentals closed for the season and will be available in May 2026. Drinking water: Water is available at the Ranger Station and Visitor Center. Bathrooms: Modern bathroom facilities are available from late April through mid-October. Vault toilets are available throughout the park. The vault toilets in the two campgrounds and the picnic grounds are available seasonally when the modern facilities are not open. Water: Water will be off beginning October 19th. During the off-season tanks can be filled with potable water behind the Ranger Station. Vault toilets will be open throughout the campground and day use area. Flushable toilets and potable water is available at the Visitor Center. Dump station: The dump station is available late April through mid-October for campers only. Campgrounds: The Savanna Campground is open year-round. The Riverway Campground is open mid-April - October. Electric sites: 30 amp max. in the Riverway Campground, 50 amp max. in the Savanna Campground Trails: The park has 12 miles of hiking trails. Dogs are permitted, but must be on a leash no longer than 6 feet and attended at all times. Showers: Shower buildings are available from late April through mid-October. Programs: Find park interpretive programming and events.
Source: official park page, checked Oct 29, 2026. Times are local to the park (America/Chicago).
Fees and passes
Per vehicle: a state park vehicle permit (one-day $7 or year-round $35) is required for every vehicle; same price for residents and nonresidents. Four free park days per year. Iron Range OHV SRA states 'There is no entrance fee'.
Statewide fee rule from Minnesota's park system; this park’s page doesn’t list its own fees.
Minnesota park passes
- Year-round vehicle permit — $35. Unlimited visits to every Minnesota state park and recreation area for 12 months from the month of purchase Details
- One-day vehicle permit — $7. One day, one vehicle Details
- Additional year-round vehicle permit — $26. Additional vehicles owned by a year-round permit holder Details
- Year-round motorcycle permit — $30. Motorcycle, 12 months Details
- One-day group permit — $5. Group vehicles, one day Details
From the Minnesota state guide. Confirm which passes this park accepts.
Reservations
- Day use
- No day-use reservation requirement mentioned
- Booking system
- Reserve MN (US eDirect)
- Phone
- 866-857-2757
We link to the official booking system rather than showing live availability, which changes minute to minute.
Pets
Dogs allowed · leash up to 6 feet
No smoking, pets, or additional shelters are allowed at any of the camper cabins. Dogs are permitted, but must be on a leash no longer than 6 feet and attended at all times.
Service animals are generally permitted where pets are not. Check with the park for specific areas.
Camping
| Campground or site type | Sites | Hookups / features | Price |
|---|---|---|---|
| Drive-in Sites The park has 114 shaded and open drive-in sites. | — | ShowersRVs up to The maximum RV length is 60 feet. Length is measured from front of tow vehicle to rear of vehicle being towed. | — |
| Electric Sites There are 71 electric sites across both campgrounds. | — | ElectricShowersRVs up to The maximum RV length is 60 feet. Length is measured from front of tow vehicle to rear of vehicle being towed. | — |
| Group Camp The park has four rustic, tent-only group camp sites. Each site has running water and vault toilets.
Sites 1, 2 and 3 accommodate up to 35 people. Riverside Camp accommodates up to 50 people. | — | Showers | — |
Camping details from the park
Drive-in Sites: The park has 114 shaded and open drive-in sites.
Electric Sites: There are 71 electric sites across both campgrounds.
RV Length Limit: The maximum RV length is 60 feet. Length is measured from front of tow vehicle to rear of vehicle being towed.
Accessible Sites — Three acessible campsites: There are three ccessible drive-in sites with electric hookup, two in Savanna Campground, one in Riverway Campground.
Group Camp: The park has four rustic, tent-only group camp sites. Each site has running water and vault toilets.
Sites 1, 2 and 3 accommodate up to 35 people. Riverside Camp accommodates up to 50 people.
From the official park page, checked Oct 29, 2026. Site counts and prices can change; confirm when booking.
Cabins and lodging
- Camper Cabins
Accessible Lodging: Vasa, Arcola and Marine Mills camper cabins are accessible.
Camper Cabins: The park has five camper cabins. No smoking, pets, or additional shelters are allowed at any of the camper cabins.
Marine Mills, Arcola and Vasa camper cabins are accessible, available year-round, and accommodate five people. Otisville sleeps six and is available year-round. Copas accommodates five people and is not heated. Copas is available only from April 1 through October 30.
More information on camper cabins.
More information on camper cabins.
Things to do
CampingHikingWinter sportsCross-country skiingRanger and interpretive programsWildlife viewing and birdingPicnickingHorseback ridingFishingSwimmingBoating
Trails
| Trail | Length | Difficulty | Notes |
|---|---|---|---|
| Groomed Cross-Country Skiing Classic (winter) | — | — | Trails are groomed for both classic and skate skiing. The park's 12 miles of skiing trails range from easy to difficult. A Great Minnesota Ski Pass is required on groomed ski trails for skiers age 16 and up.Groomed Cross-Country Skiing Classic |
| Groomed Cross-Country Skiing Skate (winter) | — | — | Trails are groomed for both classic and skate skiing. The park's 12 miles of skiing trails range from easy to difficult. A Great Minnesota Ski Pass is required on groomed ski trails for skiers age 16 and up.Groomed Cross-Country Skiing Skate |
| Snowshoe (winter) | — | — | Snowshoers are allowed only on the 1.5-mile Riverside Trail. No snowshoeing is allowed west of the visitor center. Snowshoe rentals are available at the ranger station.Snowshoe |
| Accessible (summer) | 1.5 mi | — | 1.5 miles — The Riverside Trail is an accessible 1.5 mile loop that begins at the picnic grounds. It is self-guided with interpretive signs. There are places to stop and rest approximately every 900 feet, with benches at some of these areas.AccessibleAccessible |
| Self-Guided (summer) | — | — | Riverside Trail loop, begins at picnic grounds.Self-Guided |
| Hiking (summer) | — | — | Trails range from easy to difficult, and pass through 12 miles of wooded areas, wetlands, and restored oak savanna areas.Hiking |
| Paved Bike (summer) | — | — | The park has 1.5 miles of paved bike trails.Paved Bike |
Trail descriptions from the park
Winter — Groomed Cross-Country Skiing Classic: Trails are groomed for both classic and skate skiing. The park's 12 miles of skiing trails range from easy to difficult.
A Great Minnesota Ski Pass is required on groomed ski trails for skiers age 16 and up.
Winter — Groomed Cross-Country Skiing Skate: Trails are groomed for both classic and skate skiing. The park's 12 miles of skiing trails range from easy to difficult.
Winter — Snowshoe: Snowshoers are allowed only on the 1.5-mile Riverside Trail. No snowshoeing is allowed west of the visitor center.
Snowshoe rentals are available at the ranger station.
Summer — Accessible — 1.5 miles: The Riverside Trail is an accessible 1.5 mile loop that begins at the picnic grounds. It is self-guided with interpretive signs.
There are places to stop and rest approximately every 900 feet, with benches at some of these areas.
Summer — Self-Guided: Riverside Trail loop, begins at picnic grounds.
Summer — Hiking: Trails range from easy to difficult, and pass through 12 miles of wooded areas, wetlands, and restored oak savanna areas.
Summer — Paved Bike: The park has 1.5 miles of paved bike trails.
Trail conditions: The park has 12 miles of hiking trails. Dogs are permitted, but must be on a leash no longer than 6 feet and attended at all times.
Swimming
Swimming Beach: Located in the Walter F. Mondale Day Use Area, the swimming beach at Lake Alice is closed due to the lake drawdown.
Boating and paddling
Boat Access: Located in the Walter F. Mondale Day Use Area, the park's boat access is closed due to sediment buildup in the St. Croix creating unsafe conditions for launch.
Fishing
Fishing Pier: The accessible fishing pier on Lake Alice is closed due to the lake drawdown.
A state fishing license is usually required.
Amenities
Facilities
- Restrooms
- Flush toilets
- Vault or pit toilets
- Showers
- Picnic areas
- Picnic shelters
- Visitor center
- Nature center or museum
- Park or camp store
- Group facilities
Water
- Swimming beach
- Fishing pier
Camping
- RV dump station
- Tent camping
- RV camping
- Electric hookups
- Group camping
Lodging
- Cabins
- Glamping or camper cabins
Accessibility
- Accessible cabins or lodging
✓ listed by the park · ✕ the park says it is not available. Anything not shown here isn’t mentioned by the official source — that means unknown, not unavailable.
Accessibility
- Accessible cabins or lodging
Accessible Sites — Three acessible campsites: There are three ccessible drive-in sites with electric hookup, two in Savanna Campground, one in Riverway Campground.
Accessible Lodging: Vasa, Arcola and Marine Mills camper cabins are accessible.
Camper Cabins: The park has five camper cabins. No smoking, pets, or additional shelters are allowed at any of the camper cabins.
Marine Mills, Arcola and Vasa camper cabins are accessible, available year-round, and accommodate five people. Otisville sleeps six and is available year-round. Copas accommodates five people and is not heated. Copas is available only from April 1 through October 30.
More information on camper cabins.
Showers: Accessible showers are available seasonally in the Savanna and Riverway campgrounds
Read more from the park
Flush Toilets: Accessible restrooms are available seasonally in the campground, picnic area and swimming beach. Year-round restrooms in the visitor center.
Picnic Shelter: The park has three open walled shelters. All shelters have electricity. There are two open shelters in the main picnic area; the larger one is accessible and has a fireplace. A third open shelter is located on Lake Alice, behind the beach area. Call the park to reserve.
Fishing Pier: The accessible fishing pier on Lake Alice is closed due to the lake drawdown.
Accessible — 1.5 miles: The Riverside Trail is an accessible 1.5 mile loop that begins at the picnic grounds. It is self-guided with interpretive signs.
There are places to stop and rest approximately every 900 feet, with benches at some of these areas.
All-Terrain Track Chair: The park has two all-terrain, electric powered chairs that may be used on designated trails within the park.
- Reserve the chair
- Map of designated trails
- Learn more about track chairs
Official accessibility information
Conditions change. Contact the park to confirm specific accessible features before your visit.
Getting there
- Address
- 16821 O'Brien Trail North
Marine on St. Croix, MN 55047 - Nearest town
- Forest Lake — about 10 mi east (straight line)
- Coordinates
- 45.2253, -92.7636
- Phone
- (651) 539-4980
- williamobrien.statepark@state.mn.us
Google Maps directionsApple MapsOfficial park map (PDF)
Directions from the park
The park is located 12 miles north of Stillwater. The park entrance is right on State Highway 95, 3 miles south of Highway 97 and 2 miles north of Marine on St. Croix. After turning onto the park road, the ranger station is immediately on your right. GPS coordinates: 45 13.521, -92 45.827 Using a GPS unit? Read this! If you are using a GPS unit, you must type in the following address to get to the park headquarters and main use area: 19074 St. Croix Trail North, Marine on St. Croix, MN 55047.
Nearby state parks
Sources and freshness
- Minnesota State Parks and Trails — park page — last checked Oct 29, 2026
- MN DNR A-Z list of state parks and recreation areas (park IDs in server-rendered <noscript> links) + state waysides page; details from the compass feature_detail JSON API used by park.html
- Wikidata
- USGS PAD-US 4.1 (boundary and acreage)
- Photo: Railroad Tracks.jpg — Public domain (released by the author), Powerkites16
“Last checked” is when our system last read the official source. “Last changed” (Oct 29, 2026) is when the information shown here last differed from the previous check. Hours, fees and rules can change without notice — confirm with the park before you go. Methodology