Upper Turtle Lake

Upper Turtle Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.

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. The lake bottoms out at 25 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Upper Turtle Lake covers 427 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Barron County's 37 graded lakes, Upper Turtle Lake ranks 23 — below the local median, though not at the bottom.

Upper Turtle Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery includes walleye among the lake's 4 documented species — a notable draw for Wisconsin anglers. 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.