Shell Lake

On the LakeGrade rubric, Shell Lake pulls an A: clarity at 16.0 ft and 15 µg/L of phosphorus put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI near 40 places Shell Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Shell Lake reaches 36 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. With 2,513 acres of surface and partial shoreline records, Shell Lake is a large water by Wisconsin standards — recreational pressure is spread across a long shoreline. Within Washburn County's 47 graded waters, Shell Lake sits at rank 5, near the top of the local distribution.

Shell 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. Walleye are documented at Shell Lake, one of 6 fish species on record for the lake. A documented public access point at Shell Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.