Lake Tomah

Lake Tomah earns a D — measurements through 2025 show persistent nutrient pressure that limits clarity through the summer. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

At a TSI of 65, Lake Tomah reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. 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. Lake Tomah covers 245 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins.

Lake Tomah carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. A documented public access point at Lake Tomah 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.