Johnson County Lake Quality

There are 32 monitored lakes in Johnson County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. 3 of those lakes carry an A–F grade. The county-level summary describes that subset, not every water body listed. With an average grade of B, Johnson County sits comfortably above the Wyoming median.

The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Lake Desmet Lpd (B); the most-stressed is Lake Desmet Lpd (B).