Mississippi River (near Hamilton): Geode Digging in Hancock County, Illinois

Updated June 2026

Mississippi River (near Hamilton) is a mapped rockhounding spot in Hancock County, Illinois. Reported finds include geode, amethyst, quartz. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Hancock County
State: Illinois
Postcode: 52632
Coordinates: 40.38328, -91.37654

Geology at Mississippi River (near Hamilton)

This spot sits on Meppen Limestone, Fern Glen Formation, and Burlington-Keokuk Limestone, mapped as limestone that formed roughly 360 to 330 million years ago. Limestone country like this is classic geode ground: cavities in the carbonate rock can line themselves with quartz or calcite crystals.

Mapped unit: Meppen Limestone, Fern Glen Formation, and Burlington-Keokuk Limestone
Age: 360–330 Ma (Mississippian)
Rock types: limestone
Elevation: 520 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 Mississippi River (near Hamilton)

Best months: March to November. Typical highs run 86°F in midsummer and 33°F in midwinter, with winter lows near 17°F.

Climate normals: NOAA 1991-2020 monthlies, KEOKUK L&D 19 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 Mississippi River (near Hamilton)

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 Mississippi River (near Hamilton).

Across the state line from Mississippi River (near Hamilton)

Mississippi River (near Hamilton) is close enough to the Illinois border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Mississippi River (near Hamilton) FAQ

Where is Mississippi River (near Hamilton)?+

Mississippi River (near Hamilton) is in Hancock County, Illinois, at 40.38328, -91.37654.

What rocks and minerals can you find at Mississippi River (near Hamilton)?+

Mississippi River (near Hamilton) is reported to produce Geode, Amethyst, Quartz.

Is collecting allowed at Mississippi River (near Hamilton)?+

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 Mississippi River (near Hamilton)?+

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 Mississippi River (near Hamilton)?+

The most comfortable months at Mississippi River (near Hamilton) are March to November.

How do I get to Mississippi River (near Hamilton)?+

Open the directions link to navigate to 40.38328, -91.37654 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Illinois

See all 31 Illinois spots →

Open Mississippi River (near Hamilton) on the map

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