Lost Lake

Lost Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Mesotrophic conditions dominate at Lost Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. At only 13 ft deep, Lost Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Lost Lake is small — 51 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 50 graded lakes in Sawyer County, Lost Lake sits at rank 13, above the county median.

Lost Lake has no invasive species recorded in Wisconsin state databases as of 2024, though prevention practices still apply at all access points. Bass fishing is part of the appeal: the species list runs to 2, anchored by largemouth and/or smallmouth bass. Multiple sampling years from the Wisconsin DNR Citizen Lake Monitoring Network back the grade, so the letter should hold steady absent a major watershed shift.