Cleaner Lakes Than Gurno Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Gurno Lake carries a Grade C (Fair) water quality score. Within 30 miles, 5 lakes hold a higher grade. Indian Lake (Sawyer County, Grade A, null mi away) is the closest meaningful upgrade.
Little Lac Courte Oreilles Lake
- +Two grade letters higher (C → A)
- ++2 ft water clarity
Grindstone Lake
- +Two grade letters higher (C → A)
- ++7.4 ft water clarity
- +Lower phosphorus (15 vs 25 µg/L)
Christner Lake
- +Two grade letters higher (C → A)
- ++2 ft water clarity
- +Lower phosphorus (18.5 vs 25 µg/L)
Lac Courte Oreilles Lake
- +Two grade letters higher (C → A)
- ++2.2 ft water clarity
- +Lower phosphorus (15 vs 25 µg/L)
Reading the cohort
5 cleaner lakes sit within 30 miles of Gurno Lake in the EPA water-quality dataset. With that many higher-grade neighbors close by, Gurno Lake's Grade C reflects something specific to the lake itself — not a regional water-quality ceiling. The neighbor list below isn't a small set of marginal upgrades; it's a real cohort of meaningfully cleaner choices for the same Wisconsin weekend.
The closest cleaner alternative — Indian Lake in Sawyer County, Grade A — sits miles from Gurno Lake. At that distance, the substitution cost is essentially zero: same drive time, same regional access, demonstrably cleaner water on the EPA indicators. For repeat visitors who care about clarity or phosphorus levels, swapping the routine to Indian Lake is mostly a habit change rather than a logistics change.
The EPA water-quality grading combines clarity (Secchi depth), phosphorus, and chlorophyll-a measurements from state environmental sampling. A higher letter grade reflects measurably cleaner water on those indicators, not subjective beauty or access quality — a Grade A lake might have worse boat-launch facilities or shoreline access than a Grade C neighbor, so the ranking is one input alongside the rest of trip planning. See the methodology page for the full grading formula.
How this list is built
Rated lakes on LakeQuality have a letter from EPA Water Quality Portal samples — nutrients and algae measured against EPA National Lakes Assessment ecoregion classes. Secchi is shown, not scored. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.