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 and phosphorus 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 62 of 76 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 among the lake's 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.