Catherine Lake

Catherine Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Wisconsin average.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. At only 14 ft deep, Catherine Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. At 136 acres, Catherine Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Catherine Lake ranks 32 of 33 in Iron County — at the lower end of the locally monitored distribution.

No invasive species are currently listed at Catherine Lake — the lake remains off the Wisconsin infested-waters roster. The fishery includes walleye among the lake's 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.