Bone Zone app icon

Bone Zone

Exploring Geological History

Bedrock geology for the lower 48 states, real fossil occurrences, and a verdict on what you might find beneath your feet — on iPhone.

Download on the App Store

Free on the App Store

The geologic map that fits in your pocket

Bone Zone turns state geologic survey data and paleontology databases into a fossil-hunting companion.

Geologic maps, coast to coast

Bedrock geology for the lower 48 states, colored by geologic age using the standard International Chronostratigraphic Chart — the same colors professional geologists use.

Real fossil occurrences

Documented fossil finds from the Paleobiology Database, plotted on the map so you can see exactly what has been discovered near you.

Fossil-potential verdicts

Tap anywhere and get a plain-English verdict — from "Hot Spot" to "Wrong Rock" — based on the rock type and age beneath that point.

Learning Center built in

Guides to geology, rock ages, field safety, and collecting law — the same material as this site, available offline in the app.

See it in action

Straight from the App Store — geologic layers, fossil pins, and verdicts on a real map.

Bone Zone splash with the app logo over a geologic map Formation detail panel continuing the splash panorama Bone Zone showing Arizona's geologic map covered in fossil pins Formation detail panel with a Just Right fossil-potential verdict Fossil occurrence detail view Geologic age color key matching the international time scale Learning Center guides inside the app
Quaternary Cretaceous Jurassic Triassic Devonian Ordovician Cambrian Proterozoic

Map colors follow the International Chronostratigraphic Chart, the worldwide standard for geologic time.

Fossil hunting resources

Field guides covering the geology, technique, safety, and law of responsible fossil collecting.