Roosevelt Lake

Roosevelt 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.

A TSI near 41 places Roosevelt Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 129 ft of maximum depth, Roosevelt Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. Roosevelt Lake covers 1,511 acres alongside 18.6 miles of shoreline, large enough that conditions can vary meaningfully between bays. Among the 133 graded lakes in Cass County, Roosevelt Lake sits at rank 66, above the county median.

Roosevelt 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. Muskie are on the species list at Roosevelt Lake, alongside the lake's 18 other documented fish. A documented public access point at Roosevelt Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 23 observed ice-outs, centered near Apr 19. 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.