Long Lake

On the LakeGrade scale Long Lake grades a B, with clarity at 13.5 ft and 28 µg/L of phosphorus placing it above the Wisconsin median. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Mesotrophic conditions dominate at Long Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. 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. Long Lake ranks 5 of 11 in Sauk County — solidly in the upper half of the local distribution.

Long Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Long 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.