Largest Lakes in Wyoming: Biggest by Size & Type

Wyoming’s largest lakes range from a colossal high-elevation natural lake in Yellowstone to giant reservoirs on the Green, North Platte and Wind rivers. This guide ranks the largest lakes in Wyoming by surface area, separates the biggest natural lake from the biggest reservoir, and links to a full guide for each. It’s part of our Wyoming Lakes Database.

The largest lakes in Wyoming, by size

1. Yellowstone Lake – about 87,000 acres; the largest lake in Wyoming and the largest high-elevation lake in North America.
2. Flaming Gorge Reservoir – a vast Green River reservoir (about 42,000 acres total) spanning Wyoming and Utah.
3. Jackson Lake – about 25,500 acres, the largest lake in Grand Teton National Park.
4. Pathfinder Reservoir – about 22,000 acres on the North Platte.
5. Seminoe Reservoir – about 20,000 acres on the North Platte.
6. Boysen Reservoir – about 19,500 acres on the Wind River.
7. Glendo, Keyhole, Buffalo Bill and Fontenelle reservoirs round out the big water.

The largest natural lake vs. the largest reservoir

Yellowstone Lake is both the largest lake in Wyoming and the largest natural lake – a roughly 87,000-acre high-elevation lake atop the Yellowstone supervolcano. The largest reservoir entirely or mostly in Wyoming is Flaming Gorge (shared with Utah) or, fully in-state, Pathfinder and Seminoe on the North Platte.

Where the big lakes are

Wyoming’s biggest natural lakes are in the mountains – Yellowstone, Jackson and the deep glacial lakes of the Tetons and Wind Rivers. Its biggest reservoirs are on the rivers: the North Platte chain (Pathfinder, Seminoe, Glendo), the Wind River (Boysen, Ocean Lake), the Green River (Flaming Gorge, Fontenelle) and the Shoshone (Buffalo Bill).

Frequently asked questions

What is the largest lake in Wyoming?

Yellowstone Lake, at about 87,000 acres – the largest lake in Wyoming and the largest high-elevation lake in North America.

What is the largest reservoir in Wyoming?

Flaming Gorge Reservoir (shared with Utah) is the largest; Pathfinder and Seminoe on the North Platte are the largest entirely within Wyoming.

What are the three biggest lakes in Wyoming?

Yellowstone Lake, Flaming Gorge Reservoir and Jackson Lake.

Browse the full database by Largest Lakes and Small Lakes, see our best lakes roundup, or head back to the Wyoming Lakes Database.

Quick answers about Wyoming lakes

What is the biggest lake in Wyoming?

Wyoming’s largest lake is Yellowstone Lake at about 87,000 acres – the biggest high-elevation lake in North America. The largest reservoir is Flaming Gorge on the Green River, shared with Utah.

What is the largest reservoir entirely in Wyoming?

Boysen and Seminoe reservoirs are among the largest reservoirs located entirely within Wyoming, along with Flaming Gorge (which extends into Utah).