Butternut Lake

Butternut Lake earns a D — measurements through 2025 show persistent nutrient pressure that limits clarity through the summer. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Butternut Lake reaches 15 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. Butternut Lake covers 145 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 37 graded lakes of Barron County, Butternut Lake sits at rank 30, near the bottom of the county list.

Butternut Lake has at least one documented invasive species (Purple Loosestrife), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery is bass-led, with 3 documented species across the lake's records. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.