Upper Twin Lake

Upper Twin Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. At only 12 ft deep, Upper Twin Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Upper Twin Lake covers 213 acres alongside 3.2 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Upper Twin Lake ranks 64 of 77 in Hubbard County — at the lower end of the locally monitored distribution.

Zebra mussel presence at Upper Twin Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. The fishery includes walleye alongside the lake's other 18 documented species — a notable draw for Minnesota anglers. The lake lacks a documented public access point, so visitor use is limited. 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.