Ten Sleep: Gypsum Rockhounding in Washakie County, Wyoming

Updated June 2026

Ten Sleep is a mapped rockhounding spot in Washakie County, Wyoming. Reported finds include gypsum. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Washakie County
State: Wyoming
Coordinates: 44.08364, -107.51093

Geology at Ten Sleep

This spot sits on Sundance and Gypsum Spring Formations, mapped as sandstone, shale, and dolostone that formed roughly 175 to 145 million years ago. Carbonate rock like this dissolves and weathers readily, so fresh road cuts, quarries, and creek exposures are typically the most productive ground.

Mapped unit: Sundance and Gypsum Spring Formations
Age: 175–145 Ma (Middle Jurassic to Late Jurassic)
Rock types: sandstone, shale, and dolostone
Elevation: 4,400 ft

Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.

Best time to visit Ten Sleep

Best months: March to November. Typical highs run 89°F in midsummer and 38°F in midwinter, with winter lows near 16°F.

Climate normals: NOAA 1991-2020 monthlies, TENSLEEP 4NE station (7 mi away), adjusted for elevation.

Land & collecting status

Generally open to casual rockhounding

Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.

Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.

Sources & verification

Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.

State guidance last verified: April 1, 2026

BLM Wyoming
Wyoming State Geological Survey
Fossil Butte National Monument
Community submissions reviewed against published agency rules

Found at Ten Sleep

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Gypsum Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Ten Sleep.

Ten Sleep FAQ

Where is Ten Sleep?+

Ten Sleep is in Washakie County, Wyoming, at 44.08364, -107.51093.

What rocks and minerals can you find at Ten Sleep?+

Ten Sleep is reported to produce Gypsum.

Is collecting allowed at Ten Sleep?+

Generally open to casual rockhounding. Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Ten Sleep?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Ten Sleep?+

The most comfortable months at Ten Sleep are March to November.

How do I get to Ten Sleep?+

Open the directions link to navigate to 44.08364, -107.51093 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Wyoming

See all 82 Wyoming spots →

Open Ten Sleep on the map

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