Keyhole Reservoir sits in the shadow of Devils Tower in the rolling country of northeastern Wyoming – a roughly 9,000-acre reservoir on the Belle Fourche River, ringed by Keyhole State Park on the edge of the Black Hills. Known for walleye, northern pike and abundant birdlife, with the iconic Tower rising on the horizon, it’s a relaxed, scenic lake that pairs perfectly with a visit to one of America’s most famous landmarks.
This guide covers Keyhole Reservoir: the fishing, the state park and birding, and access. It’s part of our growing Wyoming Lakes Database.
Keyhole Reservoir at a glance
- Surface area: ~9,000 acres on the Belle Fourche River (level varies)
- Location: Crook County, northeastern Wyoming (near Moorcroft & Pine Haven)
- Built: Keyhole Dam, completed 1952; the centerpiece of Keyhole State Park
- Top fish: walleye, northern pike, smallmouth bass, channel catfish, yellow perch
Fishing Keyhole Reservoir
Keyhole is a well-rounded warmwater fishery: walleye are the main draw, with strong northern pike, good smallmouth bass on the rocky structure, plus channel catfish and yellow perch. A Wyoming fishing license is required. The lake’s many coves, points and submerged structure hold fish, and it’s a popular ice-fishing destination in winter. As a Belle Fourche reservoir, its level fluctuates, so check conditions before launching.
The state park, birding and Devils Tower
Keyhole State Park wraps the reservoir with campgrounds, a marina, boat ramps and a beach, on the western edge of the Black Hills. That location makes it a surprisingly rich birding spot – over 200 species have been recorded, including pelicans, herons and Black Hills specialties. And looming on the horizon is Devils Tower, the nation’s first national monument, just a short drive away – the lake makes a great basecamp for visiting it.
Getting there and what’s nearby
Keyhole Reservoir is near Pine Haven and Moorcroft off I-90 in northeastern Wyoming, about 40 minutes west of Devils Tower and an hour from the South Dakota Black Hills. Gillette and the northeastern Wyoming energy country are nearby.
Know before you go
- Fishing license: a Wyoming license is required.
- Fluctuating level: the reservoir level varies – check before trailering a boat.
- Pair with Devils Tower: the monument is a short drive away.
Frequently asked questions
What fish are in Keyhole Reservoir?
Walleye (the headliner), northern pike, smallmouth bass, channel catfish and yellow perch.
Is Keyhole Reservoir near Devils Tower?
Yes – it’s about 40 minutes west of Devils Tower, making Keyhole State Park a popular basecamp for visiting the monument.
Where is Keyhole Reservoir?
In Crook County, northeastern Wyoming, near Pine Haven and Moorcroft off I-90.
Related: explore more of the largest lakes in Wyoming, or head back to the Wyoming Lakes Database.
