Cranberry Lake

Cranberry Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Wisconsin norms.

A TSI near 46 places Cranberry Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At only 12 ft deep, Cranberry Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Cranberry Lake covers 131 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Bayfield County's 52 graded lakes, Cranberry Lake ranks 31 — below the local median, though not at the bottom.

Cranberry Lake has no invasive species recorded in Wisconsin state databases as of 2021, though prevention practices still apply at all access points. Walleye are documented at Cranberry Lake, one of 5 fish species on record for the lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.