Ninemile Lake

On the LakeGrade scale Ninemile Lake grades a B, with clarity at 6.9 ft and 16 µg/L of phosphorus placing it above the Minnesota median. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

Mesotrophic conditions dominate at Ninemile Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Ninemile Lake reaches 40 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 297 acres and 5.3 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Among the 142 graded lakes in Lake County, Ninemile Lake sits at rank 71, above the county median.

Ninemile Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Ninemile Lake, one of 6 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. 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.