Rockhounding in Platte County, Wyoming

4 mapped rockhounding spots in Platte County. Most commonly produces agate, arsenopyrite, barite, chalcedony.

Platte County rockhounding photos

Representative spot and material photos from this county, shown where verified public image records are available.

2 photos

Minerals reported in Platte County

Standout in Platte County

Hand-picked spot in Platte County, chosen for unusual mineralogy or documented public access. Each card opens the full coordinates and access notes.

Top pick
Hartville
Public
Platte 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.
Agate, Moss Agate, Chalcedony

Spots in Platte County

Spot	Minerals	Coordinates	Access
Cooney Hills	Garnet	41.9816, -105.1138	Public
HartvilleLakeside Road	Agate Moss Agate Chalcedony	42.3221, -104.7482	Public
SunriseSunrise Highway	Arsenopyrite Barite Copper	42.3358, -104.7016	Public
WheatlandWY 34	Moonstone Labradorite	41.9392, -105.1064	Public

Neighboring counties in Wyoming

Adjacent rockhounding counties, ranked by how close their centroids sit to Platte County. A natural extension if Platte County is already on your trip plan.

Across the state line from Platte County

Rockhounding counties in neighboring states within driving range. Geology rarely respects state borders — these are often the closest mapped spots you can reach without going deeper into Wyoming.

Platte County FAQ

Where can I rockhound in Platte County, Wyoming?+

RockHoundR tracks 4 rockhounding spots in Platte County. Each entry below has coordinates, mineral notes, and access type. Always confirm local rules before collecting.

What rocks and minerals are common in Platte County?+

Spots in Platte County most often produce Agate, Arsenopyrite, Barite, Chalcedony, Copper. Individual spots can vary widely.

Are these Platte County rockhounding spots on public land?+

Most spots in this list are tagged public, but access can change with seasons, claims, and local closures. Always verify before driving out — links in the app open the right BLM, USFS, or county pages.

Plan a Platte County rockhounding trip

Open RockHoundR to see these spots on the map alongside land overlays, weather, geology, and your saved finds.