
Eutrophic Lakes in Wyoming
18 eutrophic lakes in Wyoming. High nutrients, frequent algae, reduced clarity.
Eutrophic lakes — TSI 50 to 70 — are nutrient-rich and productive, with persistent summer algal communities that drive visible reductions in clarity. These conditions are not failures; they reflect a lake doing what nutrient-loaded waters do. 18 Wyoming lakes register as eutrophic. Only 0% are deep — eutrophy correlates with shallowness, agricultural watersheds, and the kind of nutrient-input history that takes decades to shift.
Eutrophic lakes typically carry higher phosphorus and chlorophyll-a readings. The same nutrient richness that defines the trophic class shows up in those numbers.
| # | Lake | County | Clarity | Depth | TSI |
|---|---|---|---|---|---|
| 1 | Seminoe Reservoir Riverine Pelagic | Carbon | 4.4 ft | - | 55 |
| 2 | Glendo Reservoir Riverine Pelagic | Platte | 1.4 ft | - | 68 |
| 3 | Glendo Reservoir Lacustrine Pelagic | Platte | 5.2 ft | - | 50 |
| 4 | Alcova Reservoir Riverine Pelagic | Natrona | 5.8 ft | - | 52 |
| 5 | Greyrocks Reservoir | Platte | 5.4 ft | - | 50 |
| 6 | Guernsey Reservoir | Platte | 4.9 ft | - | 51 |
| 7 | Glendo Reservoir Transitional Pelagic | Platte | 5.3 ft | - | 53 |
| 8 | Ocean Lake | Fremont | 2.2 ft | - | 58 |
| 9 | Mavrakis Pond | Sheridan | 0.9 ft | - | 69 |
| 10 | Bighorn Lake | Big Horn | - | - | 62 |
| 11 | City Reservoir | Park | - | - | 64 |
| 12 | Unnamed Reservoir | Big Horn | - | - | 64 |
| 13 | South Crow Reservoir | Laramie | - | - | 53 |
| 14 | Hawk Springs Reservoir | Goshen | 1.1 ft | - | 68 |
| 15 | Sloans Lake | Laramie | 2 ft | - | 63 |
| 16 | Brooks Lake | Fremont | 6.3 ft | - | 56 |
| 17 | Yellowtail Reservoir Rpd | Big Horn | - | - | 70 |
| 18 | Rawlins Reservoir | Carbon | - | - | 63 |
All eutrophic lakes →Minnesota version →Wisconsin version →Illinois version →Michigan version →Iowa version →Ohio version →Pennsylvania version →New York version →Missouri version →Indiana version →North Dakota version →South Dakota version →Florida version →Colorado version →North Carolina version →Vermont version →Texas version →Oregon version →Arkansas version →Oklahoma version →Kansas version →Nebraska version →Nevada version →Arizona version →Idaho version →Montana version →New Mexico version →Tennessee version →Alabama version →Virginia version →Kentucky version →Utah version →Washington version →Georgia version →Massachusetts version →Ontario version →Québec version →Nova Scotia version →British Columbia version →Newfoundland and Labrador version →All Wyoming lakes →
Source: EPA National Aquatic Resource Surveys, 2026.