Rainbow Lake

On the LakeGrade scale Rainbow Lake grades a B, with clarity at 6.0 ft and 11 µg/L of phosphorus placing it above the Wisconsin median. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

Mesotrophic conditions dominate at Rainbow Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. A maximum depth of 36 ft puts Rainbow Lake in the middle of Wisconsin's depth distribution. At 148 acres, Rainbow Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Rainbow Lake sits at rank 129 of 191 in Vilas County, in the lower half of the local distribution.

Rainbow Lake has no invasive species recorded in Wisconsin state databases as of 2026, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 6 documented species — a notable draw for Wisconsin anglers. 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.