Rockhounding in Walworth County, South Dakota

1 mapped rockhounding spot in Walworth County. Most commonly produces agatized wood, opalized wood.

Walworth County rockhounding photos

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

1 photo

A cut slab of silica-permineralized fossil wood with red and purple agatized grain, the kind of agatized and opalized wood found in the Missouri River banks near Mobridge — MobridgeWalworth County, South Dakota

Minerals reported in Walworth County

Standout in Walworth County

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

Top pick
Mobridge
Public
Walworth County
The Missouri River banks and gravels around Mobridge are one of the few South Dakota localities that produce opalized wood, a blend of petrified wood and silica or precious opal, along with agatized wood. It rounds out the list with a distinctive fossil-wood material from the central Missouri River corridor.
Opalized Wood, Agatized Wood

Spots in Walworth County

Spot	Minerals	Coordinates	Access
Mobridge	Opalized Wood Agatized Wood	45.5202, -100.4125	Public

Neighboring counties in South Dakota

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

Walworth County FAQ

Where can I rockhound in Walworth County, South Dakota?+

RockHoundR tracks 1 rockhounding spot in Walworth County. Each entry below has coordinates, mineral notes, and access type. Always confirm local rules before collecting.

What rocks and minerals are common in Walworth County?+

Spots in Walworth County most often produce Agatized Wood, Opalized Wood. Individual spots can vary widely.

Are these Walworth 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 Walworth County rockhounding trip

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