Grave Lake

Grave 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.

Trophically, Grave Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. At 55 ft of maximum depth, Grave Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 373 acres, Grave Lake fits the Minnesota median for monitored lakes, with 6.2 miles of shoreline. Among the 133 graded lakes in Cass County, Grave Lake sits at rank 35, above the county median.

Grave Lake has no invasive species recorded in Minnesota state databases as of 2021, 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 Grave 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.