Mattson Lake

Mattson Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. Secchi readings are the weakest of the scored parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

Mesotrophic conditions dominate at Mattson Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Among the 31 graded lakes in Chisago County, Mattson Lake sits at rank 11, above the county median.

Mattson Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Mattson Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Mattson Lake — most use is by shoreline residents and their guests. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.