When Dinosaurs Roamed America (sometimes shortened to When Dinosaurs Roamed outside of the U.S.) is a two-hour American television program (produced in the style of a traditional nature documentary) that first aired on the Discovery Channel on July 15, 2001.[1] The show features the reign of the dinosaurs in America over the course of more than 160 million years, through five different segments, each with their own variety of flora and fauna. When Dinosaurs Roamed America premiered to 5 million viewers[2] and aired numerous times on the Discovery HD Theater's opening lineup in 2002. It was released on VHS and DVD in August 2001, and had a number of re-releases on DVD since then. When Dinosaurs Roamed America also had a limited Region 2 release on Blu-ray in 2011, bundled with Valley of the T. rex.[3]