Coralville: Silicified Coral & Calcified Coral Rockhounding in Johnson County, Iowa

Updated June 2026

Coralville is a mapped rockhounding spot in Johnson County, Iowa. Reported finds include silicified coral, calcified coral. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Johnson County
State: Iowa
Nearest road: LL Pelling Road
Postcode: 52241
Coordinates: 41.68826, -91.62417

Geology at Coralville

This spot sits on ground mapped as Cedar Valley Group that formed roughly 390 to 370 million years ago. Fossils here are typically found in fresh exposures, where erosion keeps bringing new material to the surface.

Mapped unit: Cedar Valley Group
Age: 390–370 Ma (Middle Devonian to Late Devonian)
Elevation: 680 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 Coralville

Best months: March to November. Typical highs run 86°F in midsummer and 31°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, IOWA CITY MUNI AP station (5 mi away).

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 Coralville

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 Coralville.

Across the state line from Coralville

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

Coralville FAQ

Where is Coralville?+

Coralville is in Johnson County, Iowa, at 41.68826, -91.62417. Nearest road: LL Pelling Road.

What rocks and minerals can you find at Coralville?+

Coralville is reported to produce Silicified Coral, Calcified Coral.

Is collecting allowed at Coralville?+

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 Coralville?+

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 Coralville?+

The most comfortable months at Coralville are March to November.

How do I get to Coralville?+

Open the directions link to navigate to 41.68826, -91.62417 in Google Maps. The nearest road is LL Pelling Road.

More rockhounding in Iowa

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Open Coralville on the map

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