In 2015, scientists found the first — and only — dinosaur fossil in Washington state. It was the partial thigh bone of a theropod — a group that includes raptors, t-rex, and modern birds. Dinosaur fossils have been found in every state in the west, and Washington has plenty of mammoths, mastodon, and giant sloth bones. Why is evidence of dinosaurs so rare here? Turns out, the answer has a lot to do with an epic geologic journey.