Ida Lake

Ida Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

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. The lake's 106 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 4,445 acres, Ida Lake is one of the larger lakes in Douglas County, with 22.6 miles of shoreline supporting multiple distinct use patterns. Within Douglas County's 51 graded waters, Ida Lake sits at rank 4, near the top of the local distribution.

Zebra mussels have been documented at Ida Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Ida Lake's fishery is anchored by muskellunge, with 19 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been logged at Ida Lake more than two dozen times, putting the median around Apr 16 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.