What are oligotrophic lakes in Wyoming?

20 oligotrophic lakes in Wyoming. Low nutrients, clear water, excellent for swimming.

What does oligotrophic mean?

Low nutrients, clear water, excellent for swimming.

Oligotrophic Lakes in Wyoming

An oligotrophic lake is what most people picture when they think of pristine northern lake country: clarity to depth, no algal scum, cold water that holds dissolved oxygen all the way to the bottom even in August. Across Wyoming, 20 lakes register as oligotrophic — 0% of them break 50 feet of depth, which is the structural condition that underwrites the trophic class. Without depth and a low-nutrient watershed, oligotrophy is hard to sustain.

Oligotrophic lakes almost always carry the lowest phosphorus and chlorophyll-a readings on record, since the same low-nutrient conditions produce both the trophic class and the clear water.

#	Lake	County	Clarity	Depth	TSI
1	Seminoe Reservoir Lacustrine Pelagic	Carbon	17.1 ft	-	40
2	Crystal Reservoir	Laramie	11.6 ft	-	40
3	Granite Springs Reservoir	Laramie	11.8 ft	-	39
4	Lake Desmet Lpd	Johnson	39.1 ft	-	31
5	Rob Roy Reservoir	Albany	11.2 ft	-	40
6	Half Moon Lake	Sublette	22.2 ft	-	35
7	Muddy Guard Reservoir	Johnson	15.2 ft	-	38
8	Lower New Fork Lake	Sublette	22 ft	-	35
9	Meadowlark Lake	Big Horn	11.7 ft	-	39
10	Boulder Lake	Sublette	27.7 ft	-	33
11	Lake Cameahwait	Fremont	11.6 ft	-	40
12	Fremont Lake	Sublette	42.8 ft	-	30
13	Morrison Reservoir	Platte	14.4 ft	-	38
14	Boysen Reservoir Transitional Embayment	Fremont	11 ft	-	40
15	Worthen Meadows Reservoir	Fremont	15.9 ft	-	37
16	West Newton Lake	Park	17.7 ft	-	37
17	Hog Park Reservoir	Carbon	17.9 ft	-	36
18	Hanna Reservoir	Carbon	-	-	37
19	Hanna Water Supply Lake	Carbon	-	-	37
20	Twin Lakes Reservoir D	Sheridan	-	-	37

All oligotrophic 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.