What are eutrophic lakes in Wyoming?

18 eutrophic lakes in Wyoming. High nutrients, frequent algae, reduced clarity.

What does eutrophic mean?

High nutrients, frequent algae, reduced clarity.

Eutrophic Lakes in Wyoming

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 grade C or D on our A–F scale. The same nutrient richness that defines the trophic class drives the lower grade.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Seminoe Reservoir Riverine Pelagic	Carbon	B	4.4 ft	-	55
2	Glendo Reservoir Riverine Pelagic	Platte	B	1.4 ft	-	68
3	Glendo Reservoir Lacustrine Pelagic	Platte	B	5.2 ft	-	50
4	Alcova Reservoir Riverine Pelagic	Natrona	B	5.8 ft	-	52
5	Greyrocks Reservoir	Platte	B	5.4 ft	-	50
6	Guernsey Reservoir	Platte	B	4.9 ft	-	51
7	Glendo Reservoir Transitional Pelagic	Platte	B	5.3 ft	-	53
8	Ocean Lake	Fremont	B	2.2 ft	-	58
9	Mavrakis Pond	Sheridan	B	0.9 ft	-	69
10	Bighorn Lake	Big Horn	C	-	-	62
11	City Reservoir	Park	C	-	-	64
12	Unnamed Reservoir	Big Horn	C	-	-	64
13	South Crow Reservoir	Laramie	C	-	-	53
14	Hawk Springs Reservoir	Goshen	D	1.1 ft	-	68
15	Sloans Lake	Laramie	D	2 ft	-	63
16	Brooks Lake	Fremont	D	6.3 ft	-	56
17	Yellowtail Reservoir Rpd	Big Horn	D	-	-	70
18	Rawlins Reservoir	Carbon	D	-	-	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.