Middle Cullen Lake

Middle Cullen 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.

A TSI near 40 places Middle Cullen Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 48 ft puts Middle Cullen Lake in the middle of Minnesota's depth distribution. Middle Cullen Lake covers 405 acres alongside 5.8 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Middle Cullen Lake sits at rank 68 of 120 in Crow Wing County, in the lower half of the local distribution.

Zebra mussels have been documented at Middle Cullen 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 15 documented species — a notable draw for Minnesota anglers. A documented public access point at Middle Cullen Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 16 observed ice-outs, centered near Apr 17. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.