Museum of the Rockies is a museum in Bozeman, Montana. Originally affiliated with Montana State University in Bozeman, and now also, the Smithsonian Institution. The museum is largely known for its Paleontological collections as well as having the largest collection of North American Dinosaur fossils in the United States. They also possess the largest Tyrannosaurus skull ever discovered, as well as the thigh bone of a Tyrannosaurus rex that contains soft-tissue remains. The museum is part of the Montana Dinosaur Trail and is Montana's official repository for Paleontological specimens.

Tyrannosaurus is a genus of large theropod dinosaur. The type species Tyrannosaurus rex, often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the latest Campanian-Maastrichtian ages of the Late Cretaceous period, 72.7 to 66 million years ago. It was the last known member of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.