Parker Peak: Agatized Wood & Silicified Wood Rockhounding in Fall River County, South Dakota

Updated June 2026

Parker Peak is a mapped rockhounding spot in Fall River County, South Dakota. Reported finds include agatized wood, silicified wood. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Fall River County
State: South Dakota
Coordinates: 43.40527, -103.67533

Geology at Parker Peak

This spot sits on Morrison Formation, Unkpapa Sandstone, Sundance Formation, and Gypsum Springs Formation, mapped as sandstone, siltstone, and claystone that formed roughly 175 to 145 million years ago. Sedimentary beds like these are the typical host for petrified and silicified wood, which weathers out as durable float on slopes and in washes.

Mapped unit: Morrison Formation, Unkpapa Sandstone, Sundance Formation, and Gypsum Springs Formation
Age: 175–145 Ma (Middle Jurassic to Late Jurassic)
Rock types: sandstone, siltstone, and claystone
Elevation: 4,420 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 Parker Peak

Best months: March to October. Typical highs run 85°F in midsummer and 30°F in midwinter, with winter lows near 1°F.

Climate normals: NOAA 1991-2020 monthlies, EDGEMONT station (10 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 Parker Peak

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 Parker Peak.

Across the state line from Parker Peak

Parker Peak 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.

Parker Peak FAQ

Where is Parker Peak?+

Parker Peak is in Fall River County, South Dakota, at 43.40527, -103.67533.

What rocks and minerals can you find at Parker Peak?+

Parker Peak is reported to produce Agatized Wood, Silicified Wood.

Is collecting allowed at Parker Peak?+

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 Parker Peak?+

A rock hammer, sturdy gloves, and a padded bag cover petrified wood hunting. Most pieces are surface float, so walking slopes and washes beats digging.

When is the best time to visit Parker Peak?+

The most comfortable months at Parker Peak are March to October.

How do I get to Parker Peak?+

Open the directions link to navigate to 43.40527, -103.67533 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in South Dakota

See all 43 South Dakota spots →

Open Parker Peak on the map

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