Where to Find Agate in Wyoming
Wyoming carries a small but distinctive agate roster. Sweetwater agate, from the Sweetwater River drainage in Fremont and Sublette counties, is a saturated red-and-white banded chalcedony with a translucent core, eroded out of Pleistocene gravels along old shorelines. Youngite, named for the Young Ranch near Hartville in Platte County, is a brecciated pink chalcedony with a druzy quartz coating. Petrified-wood agate turns up across the Eden Valley and Blue Forest beds in Sweetwater County, often replaced by clear-to-blue chalcedony. Smaller showings of moss and dendritic agate occur on the Powder River breaks in eastern Wyoming, mostly as small float on ranch country.
Spot list checked against source data on April 1, 2026.
Map of 23 agate collecting spots in Wyoming
Standout agate spots in Wyoming
Hand-picked from the full list below, with the reason each one earns a trip.
Laramie Mountains
Albany County County
The Laramie Mountains add a southeastern public-land agate, chalcedony, and jasper stop to a Wyoming list otherwise dominated by Sweetwater and Green River Basin material. WSGS mineral references also place the range in a broader hard-rock context, which gives the locality more geologic range than an ordinary gravel-bar agate stop.
Atlantic City
Fremont County County
Atlantic City sits in the South Pass country, where Wyoming's gold-mining history overlaps with the central Wyoming jade and agate belt. The mix of quartz, muscovite, tourmaline, jasper, chalcedony, and nephrite makes it a broader hard-rock and float locality than the single-material Sweetwater agate stops nearby.
Sweetwater River
Fremont County County
Sweetwater agate is Wyoming's signature agate, and the Sweetwater River drainage is the classic field area tied to the Granite Mountains source terrain. WSGS publications describe Sweetwater material among the state's better-known agates, while BLM rules make casual surface collecting possible on open public parcels when claims and ownership are checked first.
Warm Springs
Fremont County County
Warm Springs is a strong Granite Mountains-area pick because it combines Wyoming jade targets with agate, jasper, chalcedony, quartz, and silicified wood in one public-land collecting corridor. WSGS identifies jade as Wyoming's best-known gemstone and also lists agate, petrified wood, and quartz crystals among the state's important collector materials.
Hartville
Platte County County
Hartville is the southeastern Wyoming choice for Guernsey Limestone chalcedony, including moss agate, dendritic agate, stalactitic agate, and youngite noted by WSGS. Its appeal is the combination of lapidary-grade silica and mining-district geology in a part of the state outside the central Sweetwater jade and agate belt.
Best counties for agate in Wyoming
Ranked by the number of mapped agate spots. County links open the full rockhounding page for that county.
- Fremont County7 spots
- Sweetwater County6 spots
- Natrona County2 spots
- Albany County1 spot
- Goshen County1 spot
- Johnson County1 spot
- Park County1 spot
- Platte County1 spot
- Teton County1 spot
- Uinta County1 spot
- Washakie County1 spot
Every agate spot we track in Wyoming
Sorted by county. Coordinates open in Google Maps.
Before you go
Read the agate identification guide so you know what a keeper looks like in the field: Agate in the encyclopedia.
Agate in Wyoming FAQ
Where can you find agate in Wyoming?+
How many agate spots are mapped in Wyoming?+
Is it legal to collect agate in Wyoming?+
Where else to find agate
More minerals to hunt in Wyoming
Hunt agate in Wyoming with the map in your pocket
RockHoundR puts these spots on an offline map with BLM and Forest Service overlays, geology layers, and a log for your finds.
