Birch Lake

Birch Lake comes in at a B on the grading rubric — a respectable showing for a Wisconsin lake of its size and depth. 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 Birch Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. A maximum depth of 45 ft puts Birch Lake in the middle of Wisconsin's depth distribution. The lake's 506 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Vilas County's 191 graded lakes, Birch Lake ranks 127 — below the local median, though not at the bottom.

Birch Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery includes walleye alongside the lake's other 6 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR 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.