Willow River State Park
Willow River State Park is a state park in St. Croix County. It was established in 1967. 7 graded lakes are within 15 miles of the park, including Lake Mallalieu, Bass Lake Pump Site, Bass Lake.
Willow River State Park State Park spans an unrecorded acreage acres in Wisconsin — a designated recreation destination with the full set of facilities the state park system provides. 7 graded lakes are within easy reach of the park, with an average grade of C. Bass Lake (A) is the cleanest of the set.
State parks pair well with the LakeGrade dataset: the park itself usually has interpretive signage explaining the local lake system, but the per-lake grade tells you which actual lake in the system to head to.
Official Resources
Nearby Graded Lakes (within 15 mi)
Lakes closest to Willow River State Park, weighted by size. Click a lake for its full water quality grade, fish species, and depth.
| Lake | County | Grade | Surface Area | Distance |
|---|---|---|---|---|
| Lake Mallalieu | St. Croix | D | 270 acres | 4.2 mi |
| Bass Lake Pump Site | St. Croix | C | - | 3.2 mi |
| Bass Lake | St. Croix | A | - | 4.3 mi |
| Lake St. Croix | St. Croix | B | - | 9.3 mi |
| St. Croix 8 Mi. Upstream of Point Douglas Dr Lake | Pierce | C | - | 11.9 mi |
| Apple Lake | St. Croix | D | - | 12.1 mi |
| Cedar Lake | Polk | C | - | 14.5 mi |
Other Parks in the Area
- Kinnickinnic State Park— State Park, 13.4 mi
- Interstate Park— State Park, 25.6 mi
- Straight Lake State Park— State Park, 42.5 mi
Source: EPA National Aquatic Resource Surveys, 2026.