Swift Lake

Swift Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

Mesotrophic conditions dominate at Swift Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Swift Lake is unusually deep for Minnesota at 52 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. The lake's 357 acres and 5.6 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Cass County's 133 graded lakes, Swift Lake ranks 87 — below the local median, though not at the bottom.

Swift Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Swift Lake, one of 13 fish species on record for the lake. The lake lacks a documented public access point, so visitor use is limited. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.