Island Lake

On the LakeGrade rubric, Island Lake pulls an A: clarity at 17.0 ft and phosphorus readings still being added put it in the top bracket for 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's 51 ft maximum depth is in the upper tier for Wisconsin — deep enough for cold-water fish to find refuge in summer. Island Lake is small — 63 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Island Lake ranks 2 of 52 in Bayfield County, putting it in the upper tier of locally monitored lakes.

Island Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The fishery includes walleye among the lake's 4 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.