Upper Sioux Agency State Park
Upper Sioux Agency State Park is a state park in Minnesota. It was established in 1963. 7 graded lakes are within 15 miles of the park, including Wood Lake, Curtis Lake, Cottonwood Lake.
Upper Sioux Agency State Park State Park spans an unrecorded acreage acres in Minnesota — 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 F. Curtis Lake (D) 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 Upper Sioux Agency State Park, weighted by size. Click a lake for its full water quality grade, fish species, and depth.
| Lake | County | Grade | Surface Area | Distance |
|---|---|---|---|---|
| Wood Lake | Yellow Medicine | F | - | 4.9 mi |
| Curtis Lake | Yellow Medicine | D | 440 acres | 11.2 mi |
| Cottonwood Lake | Lyon | F | 378 acres | 13.6 mi |
| Timm Lake | Yellow Medicine | F | 260 acres | 13.7 mi |
| Tyson Lake | Yellow Medicine | D | - | 9 mi |
| Lady Slipper Lake | Lyon | F | - | 14 mi |
| School Grove Lake | Lyon | F | - | 14.9 mi |
Other Parks in the Area
- Lac qui Parle State Park— State Park, 29.4 mi
- Camden State Park— State Park, 34.3 mi
- Fort Ridgely State Park— State Park, 40.9 mi
- Monson Lake State Park— State Park, 41.5 mi
Source: EPA National Aquatic Resource Surveys, 2026.