Duplicate Lake

Duplicate Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Bayfield County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

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 maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Duplicate Lake ranks 44 of 55 in Bayfield County — at the lower end of the locally monitored distribution.

Duplicate Lake has no invasive species recorded in Wisconsin state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Duplicate Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.