North Lake

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

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 43 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 79 acres, with partial shoreline records and little volume to buffer nutrient inputs. Within Florence County's 39 graded waters, North Lake sits at rank 1, near the top of the local distribution.

North Lake is on the Wisconsin infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. The fishery includes walleye among the lake's 5 documented species — a notable draw for Wisconsin anglers. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.