Two canoes crossing open water between forested points in the Boundary Waters

Updated August 2026

Biggest Lake in Wyoming: Yellowstone Lake (84,288 acres)

Yellowstone Lake is Wyoming's largest lake per the National Park Service — Yellowstone National Park. Below: 50 Wyoming lakes ranked by surface area.

The largest lake in Wyoming is Yellowstone Lake at 84,288 acres , in Teton and Park County, according to the National Park Service — Yellowstone National Park.

See our Yellowstone Lake water-quality readings —

Source: National Park Service — Yellowstone National Park (2026-07-30). The table below ranks the Wyoming lakes in our own index by surface area.

Lakes with area data

9,411

Largest (acres)

900

Median of top 50

20/50

Reservoirs (vs natural)

Reading Wyoming's size profile

Wyoming's largest lake by surface area is Keyhole Reservoir in Crook County, spanning 9,411 acres. Most of Wyoming's biggest waters are natural basins left by glaciers, with stable shorelines and deep main basins.

Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full page with nutrient readings, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; water-quality readings come from EPA and state monitoring data.

The 50 biggest lakes in Wyoming by surface area

#	Lake	County	Surface area	Max depth
1	Keyhole Reservoir	Crook	9,411 acres	-
2	Shoshone Lake	Teton	7,073 acres	-
3	Wheatland Reservoir Number Two	Albany	6,441 acres	-
4	Fremont Lake	Sublette	5,400 acres	-
5	Wheatland Reservoir Lpd	Albany	4,792 acres	-
6	Cooper Lake	Albany	3,593 acres	-
7	Lake Hattie	Albany	3,032 acres	-
8	Bull Lake	Fremont	2,942 acres	-
9	Lewis Lake	Teton	2,775 acres	-
10	Big Sandy Reservoir	Sweetwater	2,510 acres	-
11	Alcova Reservoir Lacustrine Pelagic	Natrona	2,471 acres	-
12	Guernsey Reservoir	Platte	2,380 acres	-
13	Woodruff Narrows Reservoir	Uinta	2,312 acres	-
14	Heart Lake	Teton	2,154 acres	-
15	Willow Lake	Sublette	1,807 acres	-
16	Boulder Lake	Sublette	1,676 acres	-
17	Viva Naughton Reservoir Lpd	Lincoln	1,460 acres	-
18	Hawk Springs Reservoir	Goshen	1,328 acres	-
19	Jenny Lake	Teton	1,207 acres	-
20	James Lake	Albany	1,193 acres	-
21	Upper Sunshine Reservoir Lpd	Park	1,156 acres	-
22	Long Lake	Albany	1,125 acres	-
23	Lower Sunshine Reservoir	Park	1,049 acres	-
24	Leigh Lake	Teton	1,027 acres	-
25	Lost Creek Lake	Sweetwater	911 acres	-
26	Pilot Butte Reservoir Lpd	Fremont	900 acres	-
27	Emma Matilda Lake	Teton	891 acres	-
28	Eden Reservoir	Sweetwater	885 acres	-
29	Burnt Lake	Sublette	807 acres	-
30	Rob Roy Reservoir	Albany	801 acres	-
31	Goshen Hole Reservoir	Goshen	787 acres	-
32	Bates Creek Reservoir	Natrona	747 acres	-
33	Boysen Reservoir	Fremont	639 acres	-
34	Sulphur Creek Reservoir	Uinta	632 acres	-
35	La Prele Reservoir	Converse	617 acres	-
36	Soda Lake	Natrona	599 acres	-
37	Hog Park Reservoir	Carbon	598 acres	-
38	Two Ocean Lake	Teton	591 acres	-
39	Delusion Lake	Teton	568 acres	-
40	Meeks Cabin Reservoir	Uinta	565 acres	-
41	Hay Reservoir	Sweetwater	530 acres	-
42	Mahoney Lakes	Sweetwater	526 acres	-
43	Lower Slide Lake	Teton	509 acres	-
44	Shoshone Lake	Fremont	495 acres	-
45	Ross Lake	Fremont	487 acres	98.4 ft
46	Ray Reservoir	Fremont	465 acres	-
47	Phelps Lake	Teton	457 acres	158.8 ft
48	Bump-Sullivan Reservoir	Goshen	441 acres	-
49	Burlington Lake	Natrona	437 acres	-
50	Wheatland Reservoir	Platte	424 acres	-

Get updates on Wyoming's largest lakes

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Frequently Asked Questions

What is the largest lake in Wyoming?

Yellowstone Lake, at 84,288 acres, in Teton and Park County. Source: National Park Service — Yellowstone National Park, 2026-07-30.

How is lake surface area measured?

Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.

Are Wyoming's largest lakes natural or reservoirs?

Of the top 50 Wyoming lakes by area, 20 sit on a dammed river (reservoirs) and 30 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.

Do larger lakes have better water quality?

Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one reading can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.

How big is the typical Wyoming lake in this ranking?

Across the top 50 Wyoming lakes by surface area, the median is 900 acres (Pilot Butte Reservoir Lpd). This list is biased toward the biggest waters; the typical Wyoming lake is far smaller.

Where to stay near Wyoming's largest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Wyoming's biggest lakes.

Deepest lakes in Wyoming →Largest lakes (all states) →All Wyoming lakes →