South Long Lake

South Long Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Mesotrophic conditions dominate at South Long Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake bottoms out at 47 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. South Long Lake covers 1,309 acres alongside 9.8 miles of shoreline, large enough that conditions can vary meaningfully between bays. South Long Lake ranks 95 of 120 in Crow Wing County — at the lower end of the locally monitored distribution.

South Long Lake is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. The fishery includes walleye alongside the lake's other 17 documented species — a notable draw for Minnesota anglers. A documented public access point at South Long Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 17 observed ice-outs, centered near Apr 16. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.