Quill Lake

On the LakeGrade scale Quill Lake grades a B, with clarity at 11.5 ft and phosphorus readings still being added placing it above the Minnesota median.

A TSI near 42 places Quill Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake bottoms out at 46 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. At 85 acres, Quill Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Quill Lake ranks 42 of 187 in St. Louis County, putting it in the upper tier of locally monitored lakes.

Quill Lake has no invasive species recorded in Minnesota state databases as of 2023, though prevention practices still apply at all access points. The fishery is bass-led, with 4 documented species across the lake's records. The lake lacks a documented public access point, so visitor use is limited. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.