First Adult T. Rex Trackway Discovered in N.D.

Paleontologists have documented the first known trackway made by an adult Tyrannosaurus rex in southwestern North Dakota’s Hell Creek Formation. Discovered in 2025 by museum volunteer Kent Hups on federal land near Marmarth, the roughly 66.5-million-year-old trail stretches 23 feet and contains four three-toed footprints, each about three feet long. Researchers from the Denver Museum of Nature & Science and Liverpool John Moores University identified T. rex as the likely trackmaker based on the prints’ size and narrow toes, as well as the abundance of tyrannosaur fossils nearby. The track spacing suggests the more than seven-ton dinosaur walked at about 3.5 to 4.5 miles per hour with an estimated 13-foot stride, though the speed estimate is tentative. High-resolution 3D scans enabled detailed analysis and digital reproductions, offering rare evidence of the dinosaur’s movement and behavior. Three footprints are expected to be excavated and airlifted to the Denver museum this fall for further study.