Hell's Half Acre
US-20/26, Natrona County, WY
Natrona County, WY
A hidden gash of eroded badlands that opens without warning in the flat high plains, a maze of spires, ravines, and colored rock.
Hell's Half Acre is one of Wyoming's great roadside surprises: a sprawling badlands chasm, far larger than its name suggests, that opens suddenly in the flat high plains west of Casper. Where the surrounding country rolls away in sagebrush to the horizon, the ground here drops into a labyrinth of eroded spires, ravines, and colored rock.
Wind and water have carved the soft rock into a strange, jumbled landscape that early travelers found startling enough to name for the underworld. Long before them, Native peoples used this natural trap as a place to drive bison, and in modern times its alien look made it a Hollywood filming location. It is a small place with an outsized sense of drama.
What Guests Love
- The surprise of a deep, colorful badlands opening in otherwise flat country
- The maze of spires, hoodoos, ravines, and banded rock below the rim
- The stark, otherworldly look that drew filmmakers here
- Wide, quiet high-plains views and big Wyoming skies
Worth Knowing
- This is a rugged natural site; the rim edges and slopes are steep and loose, so keep well back and watch children
- Visitor facilities here have come and gone over the years, so plan to arrive self-sufficient with water and fuel
- There is little shade, and weather on the plains can turn quickly, so prepare for sun, wind, and sudden storms
- Respect the land's deep Native history and take nothing from the site
Details
Natrona County, WY
Learn about Hell's Half Acre
A chasm carved in the plains
Hell's Half Acre is a deep erosional scar, where a creek and the weather have cut down into soft sedimentary rock to expose a badlands of pinnacles, gullies, and steep colored walls. Despite the name, it covers far more than half an acre, spreading across many acres of broken ground below the surrounding flats.
The rock here holds fossils from the Eocene epoch, tens of millions of years old, hinting at the ancient environments once laid down in these layers. The contrast is what makes it memorable: level, ordinary plains right up to the edge, then a sudden plunge into a maze that looks like another planet.
A place of the bison drives
Long before highways crossed this country, Native peoples of the plains used Hell's Half Acre as a natural bison trap. Hunters would guide herds toward the hidden rim so that the animals, unable to see the drop until too late, would be funneled into the chasm, providing meat, hides, and materials essential to survival.
Such buffalo jumps and drive sites are found across the northern plains, and they reflect deep knowledge of the land and the animals. This chapter of the site's story deserves as much attention as its scenery, a reminder that this dramatic ground was a place of sustenance and skill for the peoples who knew it first.
Hollywood on the high plains
The otherworldly landscape of Hell's Half Acre caught the eye of filmmakers, and it stood in for an alien planet in the 1997 science-fiction movie Starship Troopers, its spires and ravines serving as a hostile world far from Earth. That brush with the movies gave the little-known site a burst of fame.
It is easy to see why. Standing on the rim with the eroded formations tumbling away below, you could imagine yourself somewhere far stranger than central Wyoming. The site has, at times, had a roadside lodge and services, which have opened and closed over the years, so it is wise to come prepared.
Wildlife, weather, and the seasons
The surrounding plains are pronghorn country, and these fast, curious animals are often seen out on the flats, along with jackrabbits, coyotes, and raptors hunting the open ground. The broken rock of the chasm shelters smaller creatures and nesting birds.
This is exposed, wind-scoured high desert, hot and bright in summer, cold and snow-swept in winter, with storms that can build fast over the plains any time of year. Spring and fall bring the most comfortable weather and the best light for photographing the eroded formations. In every season, the sudden drama of the place is the draw.
Closest Boutels
The closest Boutel™ stays, so you can turn this stop into an overnight. Each is an independently owned, editorially selected place to stay.
Things to Do Near Natrona County
Casper
About 40 miles east
Central Wyoming's largest city, on the North Platte, with trail history museums and Casper Mountain.
Hell's Half Acre overlook
At the site
Rim viewpoints along the highway looking down into the badlands chasm.
Powder River Country
To the west and north
The wide sagebrush basins and ranch country stretching on toward the Wind River and Bighorn ranges.