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 StoreFree 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.
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.
Geology & Formations
Rock types, famous fossil-bearing formations, and how to read a geologic map.
Read the guide →Tips & Tricks
Where to look, what to bring, and field techniques for finding more fossils.
Read the guide →Rock Ages
A tour of geologic time and the fossils to expect in rocks of each period.
Read the guide →Safety Guidelines
Protective gear, environmental hazards, and emergency preparedness in the field.
Read the guide →Rules & Regulations
Federal and state collecting law, permits, and where collecting is prohibited.
Read the guide →