Find Geodes: Where to Look in the US and How to Spot One

The easiest way to find a geode is to walk the creek beds and gravel bars downstream of rock layers known to contain them, looking for round, lumpy stones that look out of place. Geological surveys say the same thing in their own words: the Kentucky Geological Survey notes that in many places, creeks draining the Fort Payne and Warsaw-Salem formations are filled with geodes, and the Iowa Geological Survey points collectors to a 35-mile radius around Keokuk, Iowa.

In the West, the geodes sit in volcanic beds rather than creeks, and the reliable approach is to dig where others have already dug. The Bureau of Land Management (BLM) says the best spots at Utah's Dugway Geode Beds are areas that have been previously excavated.

Wikipedia lists Indiana, Iowa, Missouri, Illinois, Kentucky and Utah as US states where geodes are common. The details below come from the agency that manages or maps each area.

• Southeast Iowa, western Illinois and northeast Missouri (Keokuk geodes). From the lower Warsaw Formation, within about 35 miles of Keokuk, especially Lee, Henry and Van Buren counties in Iowa. Usually 2 to 6 inches, a few up to 30 inches. Mostly private land; permission required (Iowa Geological Survey).
• Kentucky. Creeks that drain the Fort Payne and Warsaw-Salem formations; the Green River area has produced geodes 2 feet across. Most are under a foot (Kentucky Geological Survey).
• Southern Indiana. RockHounding.org, a hobby site, names creeks in Monroe and Lawrence counties that cut the same Mississippian limestone belt, including Clear Creek south of Bloomington, and says most of that land is private farmland.
• Utah, Dugway Geode Beds. BLM public land in the West Desert, reached from Interstate 80 exit 99. Dark grey spheres of 2 to 4 inches, filled with clear, purple or pink quartz. Tunnelling is not allowed because the soft ground can collapse (BLM).
• California, Wiley Well District. BLM desert land about 16 miles west of Blythe off Interstate 10, reached by 15 miles of graded dirt road that other vehicles can use unless it has rained recently. The BLM suggests January or February for a visit (BLM).
• Oregon. The state rock is the thunderegg, found mainly in Crook, Jefferson, Malheur, Wasco and Wheeler counties (State Symbols USA). Most thundereggs are solid agate cores, which Wikipedia classes as nodules rather than true geodes.

Geode collecting is not permitted in Iowa's state parks, including the area near Geode State Park (Iowa Geological Survey).

Most geodes do not look special from the outside, so you are looking for shape and texture, not sparkle.

• Shape. Nearly spherical or oblong, rounder than the stones around it (Iowa and Kentucky geological surveys).
• Rind. In limestone country the outside is a bumpy, lumpy or cauliflower-like chalcedony shell (Kentucky and Iowa surveys). In volcanic beds it is a hard, dark grey ball (BLM, Dugway).
• Heft. Geodes are denser than plain limestone, so a round stone that feels heavier than expected for its size is a candidate (RockHounding.org, Indiana).
• Rattle. A loose crystal inside sometimes rattles when you shake it; our geode identification chart covers this and the tap test.

The Iowa Geological Survey does not give a way to tell a hollow geode from a solid one before you open it; it says only that hollow geodes are the most prized and that many geodes are solid throughout, with crystal growth filling most or all of the interior.

The only sourced weight test comes from RockHounding.org's Indiana guide: a geode feels noticeably heavier than an ordinary limestone cobble of the same size, because its dense chalcedony or quartz shell outweighs crumbly limestone. That test tells you a round stone is worth opening; it does not tell you whether you will find a hollow cavity or a solid centre inside.

The BLM's Dugway page lists the ways people open geodes on site: breaking them inside a cloth sack, a hammer with a chisel or centre punch, a saw with a carbide-tipped blade, or a pipe cutter, which can be rented from home-improvement stores. For a creek or desert trip, add:

• A shovel or trowel for beds like Dugway, where the geodes sit in soft grey ground below the surface.
• Eye protection for any hammer work.
• Water and a spare tyre for remote desert sites; the Dugway turnoff is about 50 miles down the old Pony Express road.
• A bag and marker to label where each geode came from. A named locality adds value, as our types of geodes page explains.

When you get home, our cracking a geode page covers opening them safely.

Where you may collect matters as much as where the geodes are.

• BLM public land. The BLM allows collecting reasonable amounts of rocks, minerals and semiprecious gemstones for non-commercial use on most of its land, but not in developed recreation sites, areas with active mining claims, or where mineral rights are privately owned. It asks collectors to check with the local field office first.
• Private land. Most Midwestern geode ground is private. The Iowa Geological Survey says permission must be secured before entering or removing rocks.
• State parks. Geode collecting is not permitted in Iowa state parks, including Geode State Park (Iowa Geological Survey). Treat any park as no-collecting until its own rules say otherwise.

Photograph each find where you picked it up, with a coin for scale, and again with any natural chip turned to the camera. RockLens suggests whether a rock is likely a geode, a nodule or an ordinary cobble from the photo. Weigh it against others of the same size before you decide which to open.

Research and drafting used AI assistance, and every statement was checked against the sources listed below. Locality facts come from the Iowa and Kentucky geological surveys, the Bureau of Land Management, State Symbols USA, Wikipedia and RockHounding.org; collecting rules from the BLM and the Iowa Geological Survey. Rules change, so confirm with the land manager before every trip.