Lower Hay Lake

Lower Hay Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Crow Wing County. 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 100 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 700 acres, Lower Hay Lake fits the Minnesota median for monitored lakes, with 4.4 miles of shoreline. Lower Hay Lake ranks 43 of 120 in Crow Wing County — solidly in the upper half of the local distribution.

Zebra mussels have been documented at Lower Hay Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. The fishery includes walleye alongside the lake's other 21 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been logged at Lower Hay Lake more than two dozen times, putting the median around Apr 20 — 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.