Rockyford: Blue Chalcedony Rockhounding in Oglala Lakota County, South Dakota

Updated July 2026

Rockyford is a mapped rockhounding spot in Oglala Lakota County, South Dakota. Reported finds include blue chalcedony. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Permission required
County: Oglala Lakota County
State: South Dakota
Nearest road: Cedar Butte Road
Coordinates: 43.49645, -102.52892

Geology at Rockyford

This spot sits on White River Group, mapped as claystone, siltstone, and sandstone that formed roughly 56 to 23 million years ago. Tough silica like agate, jasper, and chert typically weathers out of beds like these and collects as float in drainages and on deflation surfaces.

Mapped unit: White River Group
Age: 56–23 Ma (Eocene to Oligocene)
Rock types: claystone, siltstone, and sandstone
Elevation: 2,660 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.

Best time to visit Rockyford

Best months: March to November. Typical highs run 89°F in midsummer and 37°F in midwinter, with winter lows near 11°F.

Climate normals: NOAA 1991-2020 monthlies, PORCUPINE 11 N station (10 mi away), adjusted for elevation.

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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.

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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Rockyford

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

Blue Chalcedony Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Rockyford.

Across the state line from Rockyford

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

Rockyford FAQ

Where is Rockyford?+

Rockyford is in Oglala Lakota County, South Dakota, at 43.49645, -102.52892. Nearest road: Cedar Butte Road.

What rocks and minerals can you find at Rockyford?+

Rockyford is reported to produce Blue Chalcedony.

Is collecting allowed at Rockyford?+

Permission required before collecting. Requires landowner or agency permission before any collecting. Do not enter without explicit authorization. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Rockyford?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Rockyford?+

The most comfortable months at Rockyford are March to November.

How do I get to Rockyford?+

Open the directions link to navigate to 43.49645, -102.52892 in Google Maps. The nearest road is Cedar Butte Road.

More rockhounding in South Dakota

See all 43 South Dakota spots →

Open Rockyford on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.