Natural swimming hole
William O'Brien State Park, St. Croix River
River · Minnesota
Community-reported spot. Details below are compiled from public sources and are reported to be accurate — always verify locally before visiting.
About this swimming hole
William O'Brien State Park fronts the St. Croix River with a sandy beach popular with Twin Cities families. The gentle current and riverside trails make it an easy metro escape. It is one of the closest natural river swims to St. Paul.
Good to know
| Water type | River |
|---|---|
| Water temperature | 70s in summer |
| Depth | shallow entry; moderate river |
| Best season | June-August |
| Fees | MN state park vehicle permit required |
| Reservations required | No |
| Parking | state park lots |
| Amenities | swim beach, restrooms, canoe rentals, hiking trails |
| County | Washington County |
| Nearest town | Marine on St. Croix |
| Safety notes | no lifeguard; river current |
Map
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Frequently asked questions
Can you swim in William O'Brien State Park, St. Croix River?
Yes — William O'Brien State Park, St. Croix River is listed as a natural swimming spot in Minnesota. Reported water temperature: 70s in summer. Heads-up: no lifeguard; river current. There are rarely lifeguards at natural swimming holes — verify conditions locally before you go.
Does William O'Brien State Park, St. Croix River require reservations?
No reservations are required at William O'Brien State Park, St. Croix River based on current information — but verify before you go.
Is there a fee to visit William O'Brien State Park, St. Croix River?
Reported fee info: MN state park vehicle permit required. Fees can change — confirm with the official link.
When is the best time to visit William O'Brien State Park, St. Croix River?
The best season is typically June-August.