Big Marine Park Reserve
Marine on St Croix, Minnesota · on Big Marine Lake
Verified · 3 independent sources
- WATER
- lake
- ACCESS
- Designated swim area
- FEE
- $7
- SEASON
- Year-round
About Big Marine Park Reserve
Big Marine Park Reserve is a 1,800-acre Washington County regional park in Marine on St. Croix, Minnesota, built around Big Marine Lake. The swimming hole here is an official, family-friendly beach on the lake's gentle-grade shoreline, open seasonally alongside a boat launch, fishing pier, and playground, making Big Marine an easy lake to swim in.
The reserve sits in the northern St. Croix Valley of Washington County and was designated a regional park for its natural-resource features, with roughly 80% of its eventual 1,800 acres set aside for habitat preservation and protection of upland and wetland areas around Big Marine Lake.
Swimming at Big Marine Park Reserve
The county describes the beach as sitting on a gentle grade of Big Marine Lake, which it markets as good for families with children. The beach is unguarded (no lifeguards), so swimmers are responsible for their own safety, and adult supervision of children in and out of the water is required by park rules.
How to get to this swimming hole
Parking: A daily vehicle permit ($7) or annual permit ($30) is required to enter the park and use the beach lot; the adjacent motorized boat launch has 33 trailer parking spaces and can become congested with boat traffic during peak summer months.
The hike in
The swimming beach is a drive-up facility reached directly from its own parking lot; no hike is needed to reach the water. The park separately maintains summer/winter hiking trail loops elsewhere in the 1,800-acre reserve, but their names/distances are on downloadable county PDF maps that could not be read from the county's facility page as fetched.
Walk from the beach lot to the water is effectively at the parking area; no distance figure is published.
Plan your visit
Bringing kids
OK with supervision
Washington County markets the beach's gentle-grade lake shoreline as good for families, and it includes a nearby playground, but the beach is unguarded with no lifeguards on duty, so adults must supervise children in and out of the water at all times; only Coast Guard-approved life jackets are allowed (no water wings/tubes/noodles), and the adjacent motorized boat launch can add boat traffic near the swim area on busy weekends.
Parking
Paid, $7 daily vehicle permit ($30 annual)
Permit is required for any vehicle entering the park, including the beach lot. A separate 33-space trailer lot serves the adjacent motorized boat launch and is noted by the county and a third-party river-access site as prone to congestion with boat traffic on peak summer weekends.
Restrooms
Yes
Restrooms are open at the Big Marine Park Reserve beach and playground area, per Washington County's own facility page; no further detail (vault vs. flush) is published.
Hours
Beach season: Memorial Day-Labor Day, 9 a.m.-8 p.m. daily. Park overall: 6 a.m.-10 p.m. year-round (boat launch area listed separately as open until 11 p.m., no posted speed restriction). Park office: seasonal, Thu-Sun 8 a.m.-2:30 p.m., May 1-Sept 27.
On the water
Restrictions: Boat launch is described by the county as operating at 'open speed' (no stated speed limit), so it is primarily used by motorized boats; a river-access site (howsyourriver.com) notes non-motorized boaters should expect this to be a mostly-motorized facility with congestion during peak season. No electric-only or no-wake restriction is documented.
No dedicated carry-in/hand-launch access separate from the trailer boat launch was found; paddlers would share the same 33-space launch lot as motorboats.
Backstory
The park opened in 2008 and was selected as a Washington County regional park facility for its natural resource features; long-range plans call for family and group camping and additional miles of hiking and biking trails as the park continues to develop toward its full 1,800-acre footprint.
Big Marine Park Reserve: FAQ
Does Big Marine Park Reserve charge a fee?
Daily vehicle permit $7; annual vehicle permit $30 (required for all vehicles entering the park, including beach visitors).
Is Big Marine Park Reserve kid friendly?
Washington County markets the beach's gentle-grade lake shoreline as good for families, and it includes a nearby playground, but the beach is unguarded with no lifeguards on duty, so adults must supervise children in and out of the water at all times; only Coast Guard-approved life jackets are allowed (no water wings/tubes/noodles), and the adjacent motorized boat launch can add boat traffic near the swim area on busy weekends.
Do I need to hike to reach Big Marine Park Reserve?
No significant hike is required. The swimming area is close to parking and access.
Where do I park for Big Marine Park Reserve?
Permit is required for any vehicle entering the park, including the beach lot. A separate 33-space trailer lot serves the adjacent motorized boat launch and is noted by the county and a third-party river-access site as prone to congestion with boat traffic on peak summer weekends.
Can I bring a kayak or paddleboard to Big Marine Park Reserve?
No dedicated carry-in/hand-launch access separate from the trailer boat launch was found; paddlers would share the same 33-space launch lot as motorboats.
When is the best time to visit Big Marine Park Reserve?
Beach season runs Memorial Day through Labor Day, 9 a.m.-8 p.m. daily; the park itself is open 6 a.m.-10 p.m. year-round, with the park office open seasonally Thursday-Sunday, 8 a.m.-2:30 p.m., May 1-September 27.
What are the rules at Big Marine Park Reserve?
Beach is unguarded with no scheduled safety breaks. Only Coast Guard-approved life jackets are permitted; other flotation devices (water wings, tubes, noodles, kickboards) are prohibited. Alcohol, 3.2% beer, glass containers, and cannabis are banned on the beach; smoking is restricted to grassy areas. Dogs are not allowed on the beach (leashed dogs permitted on trails only). Children must be supervised by an adult on shore and in the water; swim diapers required for young children. Swimmers must exit the water immediately at thunder/lightning and wait 30 minutes before re-entering. Group swims require advance approval (7+ days) and a $20 daily bus permit.
What water body is Big Marine Park Reserve on?
Big Marine Park Reserve is on Big Marine Lake, a natural lake verified in USGS hydrography data.
