Donnellson: Geode Digging in Lee County, Iowa

Updated June 2026

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

Quick details

Access: Public area
County: Lee County
State: Iowa
Nearest road: 180th Avenue
Postcode: 52625
Coordinates: 40.62752, -91.56976

Geology at Donnellson

This spot sits on ground mapped as Pella Fm and St. Louis Fm that formed roughly 340 to 325 million years ago. Geodes typically weather free of their host rock and collect as rounded float in soils and drainages.

Mapped unit: Pella Fm and St. Louis Fm
Age: 340–325 Ma (Mississippian)
Elevation: 630 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 Donnellson

Best months: March to November. Typical highs run 87°F in midsummer and 33°F in midwinter, with winter lows near 16°F.

Climate normals: NOAA 1991-2020 monthlies, DONNELLSON station (1 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 Donnellson

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 Donnellson.

Across the state line from Donnellson

Donnellson 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.

Donnellson FAQ

Where is Donnellson?+

Donnellson is in Lee County, Iowa, at 40.62752, -91.56976. Nearest road: 180th Avenue.

What rocks and minerals can you find at Donnellson?+

Donnellson is reported to produce Geode.

Is collecting allowed at Donnellson?+

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 Donnellson?+

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 Donnellson?+

The most comfortable months at Donnellson are March to November.

How do I get to Donnellson?+

Open the directions link to navigate to 40.62752, -91.56976 in Google Maps. The nearest road is 180th Avenue.

More rockhounding in Iowa

See all 49 Iowa spots →

Open Donnellson on the map

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