The clean waters and sandbars of the St. Croix and Namekagon Rivers provide enticing opportunities to cool off on a hot day.

The National Park Service maintains no designated swimming beaches. WI Interstate Park and William O'Brien State Park both have beaches on lakes near the river.

All rivers present hazards to swimmers. Currents make swimming more difficult, which may cause swimmers to overestimate their abilities. A river's bed is dynamic; sandbars and drop-offs may not remain in the same place. For this reason jumping from bridges, cliffs or rope swings is not allowed.

Swimming is banned from the Highway 8 bridge at St. Croix Falls downstream to the boat launch at Wisconsin Interstate Park due to dangerous conditions and 30 previous fatalities. Swimming is not recommended near the former site of Nevers Dam as undertows and eddies exist.

Young children can drown in relatively shallow water. Do not leave them unattended and have them wear a lifejacket when in or on the water.