Gull Lake

Gull Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 29 puts Gull Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake bottoms out at 19 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. At 518 acres, Gull Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within the 48 graded lakes of Washburn County, Gull Lake sits at rank 37, near the bottom of the county list.

Gull Lake has at least one documented invasive species (Banded Mystery Snail), 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. A documented public access point at Gull Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.