Hill City: Beryl & Red Cassiterite Rockhounding in Pennington County, South Dakota

Plan your visit

Generally open to casual rockhounding

County

Pennington County

State

South Dakota

Nearest road

Campaign Hill Road

Postcode

57745

Coordinates

43.93329, -103.59407

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

Land & collecting status

Generally open to casual rockhounding

Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.

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.

Best time to visit Hill City

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 81°F in midsummer and 39°F in midwinter, with winter lows near 8°F.

Climate normals: NOAA 1991-2020 monthlies, HILL CITY station (2 mi away), adjusted for elevation.

Geology at Hill City

This spot sits on ground mapped as Metamorphosed black shale that formed roughly 2500 to 1600 million years ago. Sedimentary rock like this erodes unevenly, so the most productive collecting is typically along fresh cuts, badland slopes, and active drainages.

Mapped unit

Metamorphosed black shale

Age

2500–1600 Ma (Paleoproterozoic)

Elevation

5,370 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.

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.

• BLM Montana-Dakotas rockhounding rules
• Buffalo Gap National Grassland
• South Dakota Geological Survey
• Community submissions reviewed against published agency rules