Chapin: Geode Digging in Franklin County, Iowa

Updated June 2026

Chapin is a mapped rockhounding spot in Franklin County, Iowa. Reported finds include geode. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Franklin County
State: Iowa
Nearest road: Olive Avenue
Postcode: 50475
Coordinates: 42.85426, -93.22028

Geology at Chapin

This spot sits on ground mapped as Fammenian that formed roughly 370 to 360 million years ago. Geodes typically weather free of their host rock and collect as rounded float in soils and drainages.

Mapped unit: Fammenian
Age: 370–360 Ma (Late Devonian)
Elevation: 1,110 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 Chapin

Best months: April to November. Typical highs run 83°F in midsummer and 25°F in midwinter, with winter lows near 8°F.

Climate normals: NOAA 1991-2020 monthlies, HAMPTON station (7 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 Chapin

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

Geode Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Chapin.

Across the state line from Chapin

Chapin 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.

Blue EarthFaribault County, Minnesota · 70 mi awayLake Superior Agate

Chapin FAQ

Where is Chapin?+

Chapin is in Franklin County, Iowa, at 42.85426, -93.22028. Nearest road: Olive Avenue.

What rocks and minerals can you find at Chapin?+

Chapin is reported to produce Geode.

Is collecting allowed at Chapin?+

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 Chapin?+

Bring a crack hammer, a chisel, safety glasses, and a bucket. Candidates are rounder and lighter than solid rock; a soil pipe cutter opens them cleaner than a flat smash.

When is the best time to visit Chapin?+

The most comfortable months at Chapin are April to November.

How do I get to Chapin?+

Open the directions link to navigate to 42.85426, -93.22028 in Google Maps. The nearest road is Olive Avenue.

More rockhounding in Iowa

See all 49 Iowa spots →

Open Chapin on the map

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