Big Stony Lake

On the LakeGrade rubric, Big Stony Lake pulls an A: clarity at 10.3 ft and 11 µg/L of phosphorus put it in the top bracket for Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI near 41 places Big Stony Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 24 ft puts Big Stony Lake in the middle of Minnesota's depth distribution. The lake's 343 acres and 5.2 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Big Stony Lake sits at rank 50 of 77 in Hubbard County, in the lower half of the local distribution.

Big Stony Lake has no invasive species recorded in Minnesota state databases as of 2023, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 11 documented species — a notable draw for Minnesota anglers. A documented public access point at Big Stony Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been recorded 6 times at Big Stony Lake, with a median around Apr 24. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.