North Twin Lake

On the LakeGrade scale North Twin Lake grades a B, with clarity at 8.5 ft and 17 µg/L of phosphorus placing it above the Minnesota median. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. A maximum depth of 16 ft puts North Twin Lake in the middle of Minnesota's depth distribution. At 966 acres, North Twin Lake fits the Minnesota median for monitored lakes, with 5.7 miles of shoreline. Among the 16 graded lakes in Mahnomen County, North Twin Lake sits at rank 5, above the county median.

Zebra mussel presence at North 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 14 documented species — a notable draw for Minnesota anglers. No formal public access is documented at North Twin Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.