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.
Every agate spot we track in Wyoming
Best spotAtlantic CityFremont County, WyomingPublic access · Agate, Chalcedony, Gold +8- Best spotWarm SpringsFremont County, WyomingPublic access · Agate, Chalcedony, Jasper +4
- Best spotHartvillePlatte County, WyomingPublic access · Agate, Moss Agate, Chalcedony
- Best spotLaramie MountainsAlbany County, WyomingPublic access · Agate, Chalcedony, Jasper
Best spotSweetwater RiverFremont County, WyomingPermission required · Agate
Sweetwater CountySweetwater County, WyomingPublic access · Agate, Chalcedony, Chert +5
BuffaloJohnson County, WyomingPermission required · Agate, Chalcedony, Gastrolith +3- FarsonSweetwater County, WyomingPublic access · Agate, Chalcedony, Chert +3
- Red DesertSweetwater County, WyomingPublic access · Agate, Chalcedony, Chert +3
- Rock SpringsSweetwater County, WyomingPublic access · Agate, Chalcedony, Chert +3
- WorlandWashakie County, WyomingPermission required · Agate, Chalcedony, Red Jasper +2
- Green RiverSweetwater County, WyomingPublic access · Agate, Chalcedony, Jasper +1
- Guernsey Platte RiverGoshen County, WyomingPublic access · Agate, Chalcedony, Banded Iron Formation +1
- Steamboat MountainSweetwater County, WyomingPermission required · Agate, Chalcedony, Jasper +1
- Thorofare WildernessTeton County, WyomingPermission required · Agate, Jasper, Opalized Wood +1
- CasperNatrona County, WyomingPublic access · Agate, Alabaster, Amazonite
- Fort BridgerUinta County, WyomingPublic access · Agate, Jasper, Silicified Agate
- Fremont CountyFremont County, WyomingPublic access · Agate, Chalcedony, Jasper
- Jay EmGoshen County, WyomingPublic access · Agate, Malachite, Onyx
- LanderFremont County, WyomingPublic access · Agate, Jasper, Nephrite
- Poison Spider CreekNatrona County, WyomingPublic access · Agate, Chalcedony, Jasper
- Sage Hen CreekFremont County, WyomingPublic access · Agate, Chalcedony, Jasper
- Wind River & StreamsFremont County, WyomingPermission required · Agate, Chalcedony, Jasper
- MeeteetsePark County, WyomingPublic access · Agate, Jasper
Standout agate spots in Wyoming
Hand-picked from the full list above, with the reason each one earns a trip.
Laramie Mountains
Albany 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.
Atlantic City
Fremont County
Atlantic City sits in the South Pass country, where Wyoming's gold-mining history overlaps with the central Wyoming jade and agate belt.
Sweetwater River
Fremont 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.
Warm Springs
Fremont 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.
Hartville
Platte County
Hartville is the southeastern Wyoming choice for Guernsey Limestone chalcedony, including moss agate, dendritic agate, stalactitic agate, and youngite noted by WSGS.
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
- Goshen County2 spots
- Natrona County2 spots
- Albany County1 spot
- Johnson County1 spot
- Park County1 spot
- Platte County1 spot
- Teton County1 spot
- Uinta County1 spot
- Washakie County1 spot
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.
