Little Crab Lake

Little Crab Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in 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.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. The lake bottoms out at 26 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 73 acres, with partial shoreline records and little volume to buffer nutrient inputs. Within Vilas County's 202 graded lakes, Little Crab Lake ranks 110 — below the local median, though not at the bottom.

Little Crab Lake has no invasive species recorded in Wisconsin state databases as of 2020, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 3 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR public-access list. 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.