Little Portage Lake

On the LakeGrade rubric, Little Portage Lake pulls an A: clarity at 20.5 ft and 21 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI near 41 places Little Portage Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At only 11 ft deep, Little Portage Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. At 160 acres, Little Portage Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within the 202 graded lakes of Vilas County, Little Portage Lake sits at rank 166, near the bottom of the county list.

Little Portage Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The fishery is bass-led, with 4 documented species across the lake's records. 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.