Lake DeSmet is a deep, mysterious natural lake in the foothills of the Bighorn Mountains near Buffalo, Wyoming – famous for trophy trout, a resident lake-monster legend, and big, windy water that draws anglers from across the northern plains. Set against the dramatic backdrop of the Bighorns, it’s one of the best big-trout fisheries in the state and a longtime favorite of Buffalo and Sheridan-area anglers.
This guide covers Lake DeSmet: the trophy fishing, the legend, the recreation, and access. It’s part of our growing Wyoming Lakes Database.
Lake DeSmet at a glance
- Surface area: ~3,600 acres; deep, natural alkaline lake (enlarged for storage)
- Location: Johnson County, north-central Wyoming (near Buffalo)
- Named for: Father Pierre-Jean De Smet, the Jesuit missionary
- Top fish: trophy rainbow trout, lake trout, brown trout, rock bass, yellow perch, crappie, ling
Trophy fishing
Lake DeSmet has a statewide reputation for big trout. Its deep, fertile, alkaline water grows fast, heavy rainbow trout, along with lake trout and brown trout, and an unusual mix of warmwater species: rock bass, yellow perch, crappie and ling (burbot). A Wyoming fishing license is required. Anglers troll and still-fish for the trophy trout, and the lake is a strong ice-fishing destination in winter. The wind here is legendary – watch the forecast, as DeSmet can turn rough fast.
The legend of “Smetty”
Like many deep lakes, DeSmet has its own lake-monster legend. Local stories – some dating to Native American and early settler accounts – tell of a large creature in the depths, affectionately nicknamed “Smetty.” Whether tall tale or trick of the deep, alkaline water, it adds a dash of folklore to a lake already full of character.
Recreation and access
Public access areas with boat ramps and a campground serve the lake, supporting boating, fishing and camping against the backdrop of the Bighorn Mountains. It’s a no-frills, fishing-focused destination rather than a developed resort – the draw is the big trout and the big sky. The historic town of Buffalo, with its Occidental Hotel and Bozeman Trail history, is just minutes away.
Getting there and what’s nearby
Lake DeSmet is just north of Buffalo off I-90/I-25 in north-central Wyoming, about 30 minutes south of Sheridan. The Bighorn Mountains, the Cloud Peak Wilderness and the historic Bozeman Trail country surround it.
Know before you go
- Fishing license: a Wyoming license is required.
- Wind: DeSmet is notoriously windy – check the forecast and respect the rough water.
- Best seasons: spring and fall for trophy trout; winter for ice fishing.
Frequently asked questions
What fish are in Lake DeSmet?
Trophy rainbow trout, lake trout and brown trout, plus rock bass, yellow perch, crappie and ling – a renowned big-trout lake.
Does Lake DeSmet have a monster?
By legend, yes – local folklore tells of a creature nicknamed “Smetty” in the deep lake, a story dating back generations.
Where is Lake DeSmet?
Just north of Buffalo in Johnson County, north-central Wyoming, off I-90/I-25.
Related: explore more of the largest lakes in Wyoming, or head back to the Wyoming Lakes Database.
