Lost Lake

Lost Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Marinette County. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI near 41 places Lost Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 18 ft puts Lost Lake in the middle of Wisconsin's depth distribution. Lost Lake is small — 41 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Marinette County's 21 graded waters, Lost Lake sits at rank 3, near the top of the local distribution.

No invasive species are currently listed at Lost Lake — the lake remains off the Wisconsin infested-waters roster. The fishery is bass-led, with 1 documented species across the lake's records. A documented public access point at Lost Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.