Hell Canyon: Banded Agate & Jade Rockhounding in Custer County, South Dakota

Updated June 2026

Hell Canyon is a mapped rockhounding spot in Custer County, South Dakota. Reported finds include banded agate, jade, jasper, geode, fossils. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Custer County
State: South Dakota
Nearest road: Hell Canyon Trail
Coordinates: 43.74935, -103.84205

Geology at Hell Canyon

This spot sits on ground mapped as Pahasapa Limestone that formed roughly 360 to 330 million years ago. Limestone like this typically forms in ancient seas, so marine fossils such as brachiopods, corals, and crinoids tend to weather out of fresh exposures.

Mapped unit: Pahasapa Limestone
Age: 360–330 Ma (Early Mississippian)
Elevation: 5,440 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 Hell Canyon

Best months: April to October. Typical highs run 81°F in midsummer and 32°F in midwinter, with winter lows near 7°F.

Climate normals: NOAA 1991-2020 monthlies, EDGEMONT 23 NNW station (9 mi away), adjusted for elevation.

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.

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 Hell Canyon

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

Nearby rockhounding spots

Other rockhounding spots within driving distance of Hell Canyon.

Across the state line from Hell Canyon

Hell Canyon 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.

Hell Canyon FAQ

Where is Hell Canyon?+

Hell Canyon is in Custer County, South Dakota, at 43.74935, -103.84205. Nearest road: Hell Canyon Trail.

What rocks and minerals can you find at Hell Canyon?+

Hell Canyon is reported to produce Banded Agate, Jade, Jasper, Geode, Fossils.

Is collecting allowed at Hell Canyon?+

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. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Hell Canyon?+

A rock hammer, a cold chisel, safety glasses, and newspaper or foam for wrapping finds cover most fossil ground. A trowel and a sieve help in soft exposures.

When is the best time to visit Hell Canyon?+

The most comfortable months at Hell Canyon are April to October.

How do I get to Hell Canyon?+

Open the directions link to navigate to 43.74935, -103.84205 in Google Maps. The nearest road is Hell Canyon Trail.

More rockhounding in South Dakota

See all 43 South Dakota spots →

Open Hell Canyon on the map

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