Long Interlaken Lake Deep

Long Interlaken Lake Deep 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.

Trophically, Long Interlaken Lake Deep reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Long Interlaken Lake Deep is unusually deep for Wisconsin at 65 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Long Interlaken Lake Deep covers 380 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Vilas County's 202 graded lakes, Long Interlaken Lake Deep ranks 113 — below the local median, though not at the bottom.

Long Interlaken Lake Deep has at least one documented invasive species (Banded Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Long Interlaken Lake Deep, one of 6 fish species on record for the 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.