Mary Lake

Mary Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. 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. A maximum depth of 45 ft puts Mary Lake in the middle of Minnesota's depth distribution. Mary Lake covers 212 acres alongside 4.4 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Mary Lake ranks 70 of 141 in Itasca County — solidly in the upper half of the local distribution.

Mary Lake has no invasive species recorded in Minnesota state databases as of 2021, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Mary Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Mary 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.