North Crab Lake

North Crab Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 35 ft puts North Crab Lake in the middle of Wisconsin's depth distribution. At 59 acres, North Crab Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Within the 191 graded lakes of Vilas County, North Crab Lake sits at rank 152, near the bottom of the county list.

No invasive species are currently listed at North Crab Lake — the lake remains off the Wisconsin infested-waters roster. The fishery includes walleye alongside the lake's other 6 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.