Black Oak Lake

The LakeGrade rubric puts Black Oak Lake at a C: clarity at 9.5 ft, phosphorus readings still being added, and a TSI of 45 signal an intermediate trophic state.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. The lake bottoms out at 19 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Black Oak Lake is small — 95 acres alongside 3.4 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 55 graded lakes in Stearns County, Black Oak Lake sits at rank 27, above the county median.

Black Oak Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The fishery includes walleye among the lake's 9 documented species — a notable draw for Minnesota anglers. A documented public access point at Black Oak Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.