Spider Lake

Spider Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Cass County. 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 17 ft puts Spider Lake in the middle of Minnesota's depth distribution. At 145 acres, Spider Lake fits the Minnesota median for monitored lakes, with 4.5 miles of shoreline. Among the 133 graded lakes in Cass County, Spider Lake sits at rank 58, above the county median.

Spider Lake has no invasive species recorded in Minnesota state databases as of 2020, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 8 documented species — a notable draw for Minnesota anglers. A documented public access point at Spider Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.