Montana Lake

On the LakeGrade rubric, Montana Lake pulls an A: clarity at 26.2 ft and 18 µg/L of phosphorus put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. A maximum depth of 28 ft puts Montana Lake in the middle of Wisconsin's depth distribution. At 143 acres, Montana Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Montana Lake ranks 20 of 22 in Marinette County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil has been documented at Montana Lake, requiring shoreline management to keep dense mats from crowding native vegetation. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.