Big Sand Lake

Big Sand Lake earns an A — every scored parameter (clarity and phosphorus) rates among the best monitored waters in Burnett County. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

A TSI near 44 places Big Sand Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Big Sand Lake is unusually deep for Wisconsin at 55 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. With 1,434 acres of surface and partial shoreline records, Big Sand Lake is a large water by Wisconsin standards — recreational pressure is spread across a long shoreline. Within Burnett County's 57 graded waters, Big Sand Lake sits at rank 8, near the top of the local distribution.

Big Sand 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 among the lake's 5 documented species — a notable draw for Wisconsin anglers. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.