Oligotrophic Lakes in Wyoming

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

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 {{stateName}}, 30 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.

On the LakeGrade rubric, oligotrophic lakes almost always pull an A or B — the same low-nutrient conditions that produce the trophic class also produce the high grade.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Flaming Gorge Reservoir	Sweetwater	A	22 ft	-	34
2	Nla Lake	Sublette	A	25.3 ft	-	31
3	West Thumb Lake	Teton	A	31.2 ft	-	28
4	Yellowstone Lake	Teton	A	28.7 ft	-	29
5	Yellowstone Lake	Teton	A	26.2 ft	-	30
6	Flaming Gorge-Green River Lake	Sweetwater	A	18.4 ft	-	37
7	Yellowstone Lake @ East Side of Stevenson Island	Teton	A	27.1 ft	-	30
8	Flaming Gorge Lake	Sweetwater	A	17.4 ft	-	36
9	Yellowstone Lake	Teton	A	25.4 ft	-	30
10	Yellowstone Lake	Teton	A	25.4 ft	-	30
11	Lake Desmet Lpd	Johnson	A	39.1 ft	-	24
12	Lake Desmet Rtpd	Johnson	A	34.6 ft	-	26
13	Half Moon Lake	Sublette	A	22.2 ft	-	32
14	Lower New Fork Lake	Sublette	A	22 ft	-	33
15	Boulder Lake	Sublette	A	27.7 ft	-	29
16	Fremont Lake	Sublette	A	42.8 ft	-	30
17	Lak Reservoir	Weston	A	22.4 ft	-	32
18	Worthen Meadows Reservoir	Fremont	A	15.9 ft	-	37
19	Inlet Arizona Island Lake	Teton	A	17.5 ft	-	36
20	Leeks Marina North Lake	Teton	A	16.4 ft	-	37
21	Moran Bay Lake	Teton	A	18.3 ft	-	35
22	West Newton Lake	Park	A	17.7 ft	-	36
23	Hog Park Reservoir	Carbon	A	17.9 ft	-	36
24	Twin Lakes Reservoir D	Sheridan	A	-	-	37
25	Flaming Gorge Res Bl Buckboard Replicate of Lake	Sweetwater	A	12.6 ft	-	35
26	Crystal Reservoir	Laramie	A	11.6 ft	-	40
27	Granite Springs Reservoir	Laramie	A	11.8 ft	-	40
28	Rob Roy Reservoir	Albany	A	11.2 ft	-	40
29	Tie Hack Reservoir	Johnson	A	12.9 ft	-	39
30	Morrison Reservoir	Platte	A	14.4 ft	-	38

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 →All Wyoming lakes →

Source: EPA National Aquatic Resource Surveys, 2026.