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Hyattville: Fossil Hunting in Big Horn County, Wyoming

Public access4 mineralsBig Horn County, WyomingUpdated June 2026
Minerals reported
4
Elevation
5,050 ft
Best months
March to November

Hyattville is a mapped rockhounding spot in Big Horn County, Wyoming. Reported finds include gypsum, dinosaur bone, gastrolith, fossil. Below: coordinates, access notes, nearby spots, and trip-planning links.

Plan your visit

Generally open to casual rockhounding

State
Wyoming
Nearest road
Rea Grove Lane
Get directionsView on Google Maps

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

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.

Best time to visit Hyattville

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 87°F in midsummer and 36°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, TENSLEEP 4NE station (14 mi away), adjusted for elevation.

Geology at Hyattville

This spot sits on Sundance and Gypsum Spring Formations, mapped as sandstone, shale, and dolostone that formed roughly 175 to 145 million years ago. Limestone like this typically forms in ancient seas, so marine fossils such as brachiopods, corals, and crinoids tend to weather out of fresh exposures.

Mapped unit
Sundance and Gypsum Spring Formations
Age
175–145 Ma (Middle Jurassic to Late Jurassic)
Rock types
sandstone, shale, and dolostone
Elevation
5,050 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.

Today's weather

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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:

Found at Hyattville

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

Nearby rockhounding spots

Other rockhounding spots within driving distance of Hyattville.

  • Ten SleepWashakie County, Wyoming · 11 mi awayGypsum
  • Red GulchBig Horn County, Wyoming · 24 mi awayGypsum
  • WorlandWashakie County, Wyoming · 27 mi awayAgate, Chalcedony, Red Jasper
  • GreybullBig Horn County, Wyoming · 31 mi awayGastrolith, Petrified Dinosaur Bone, Fossil
  • LovellBig Horn County, Wyoming · 46 mi awayFossil, Ammonite, Dinosaur Bone
  • LovellBig Horn County, Wyoming · 49 mi awayGypsum, Fossil
  • BuffaloJohnson County, Wyoming · 50 mi awayAgate, Chalcedony, Gastrolith
  • ThermopolisHot Springs County, Wyoming · 51 mi awaySelenite, Travertine

Across the state line from Hyattville

Hyattville is close enough to the Wyoming border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Hyattville FAQ

Where is Hyattville?+
Hyattville is in Big Horn County, Wyoming, at 44.24413, -107.52598. Nearest road: Rea Grove Lane.
What rocks and minerals can you find at Hyattville?+
Hyattville is reported to produce Gypsum, Dinosaur Bone, Gastrolith, Fossil.
Is collecting allowed at Hyattville?+
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 Hyattville?+
A rock hammer, a cold chisel, safety glasses, and newspaper or foam for wrapping finds cover most fossil ground. A trowel and a sieve help in soft exposures.
When is the best time to visit Hyattville?+
The most comfortable months at Hyattville are March to November.
How do I get to Hyattville?+
Open the directions link to navigate to 44.24413, -107.52598 in Google Maps. The nearest road is Rea Grove Lane.

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