Mazaska Lake

On the LakeGrade rubric Mazaska Lake fails the cutoffs — a TSI of 67 and persistent algal pressure put it in the bottom tier. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.

At a TSI of 67, Mazaska Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. At 50 ft of maximum depth, Mazaska Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. Mazaska Lake covers 688 acres alongside 4.9 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Mazaska Lake ranks 10 of 12 in Rice County — at the lower end of the locally monitored distribution.

Mazaska Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. The fishery includes walleye among the lake's 17 documented species — a notable draw for Minnesota anglers. A documented public access point at Mazaska Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been recorded 19 times at Mazaska Lake, with a median around Apr 6. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.