Rog Lake

Rog Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Cook County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 30 puts Rog Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Rog Lake reaches 40 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 54 acres, Rog Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Within Cook County's 128 graded waters, Rog Lake sits at rank 26, near the top of the local distribution.

No invasive species are currently listed at Rog Lake — the lake remains off the Minnesota infested-waters roster. The fishery is bass-led, with 4 documented species across the lake's records. No formal public access is documented at Rog Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.