Quill Lake

Quill Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Quill Lake reaches 46 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. Quill Lake is small — 85 acres alongside 2.8 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within St. Louis County's 187 graded lakes, Quill Lake ranks 130 — below the local median, though not at the bottom.

Quill Lake has no invasive species recorded in Minnesota state databases as of 2022, 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.