Trillium Lake

Trillium 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.

Mesotrophic conditions dominate at Trillium Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake bottoms out at 48 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Trillium Lake covers 155 acres alongside 4.6 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Trillium Lake sits at rank 72 of 133 in Cass County, in the lower half of the local distribution.

No invasive species are currently listed at Trillium Lake — the lake remains off the Minnesota infested-waters roster. Bass fishing is part of the appeal: the species list runs to 8, anchored by largemouth and/or smallmouth bass. No formal public access is documented at Trillium Lake — most use is by shoreline residents and their guests. 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.