Thirteen Lake

Thirteen Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth.

Trophically, Thirteen Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. A maximum depth of 17 ft puts Thirteen Lake in the middle of Minnesota's depth distribution. At 80 acres, Thirteen Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Thirteen Lake ranks 53 of 187 in St. Louis County — solidly in the upper half of the local distribution.

Thirteen Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Thirteen Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.