Geology
Fossils
28 destinations along 25 roads
Before the desert there was an ocean, and the ocean left its dead. Western Utah's Cambrian shales hold trilobites by the millions — half-billion-year-old arthropods that crawled a shallow sea floor, none more common than little Elrathia kingii, the trilobite you've probably held without knowing its name. At a handful of quarries near Delta you split the gray shale yourself and keep whatever falls out. Deep time here isn't behind glass; it's a rock you crack open.