The 66.3-million-year-old T. rex was discovered in the Hell Creek Formation in northern Montana—an area that is world-famous for its fossil dinosaur sites. With permits to research and collect on federal land, the team of more than 45 people, led by Burke Museum Adjunct Curator of Vertebrate Paleontology and University of Washington associate biology professor Dr. Greg Wilson, helped excavate the T. rex over the course of a month this summer.

“When we started to see those teeth with the skull, we knew we had a fantastic specimen,” said Wilson. Not only is it a fantastic specimen, it is incredibly rare. Although arguably the most iconic and well-known species of dinosaur, the T. rex skull is one of only about 15 reasonably complete ones known to exist in the world.

Here’s how the discovery unfolded…