A high school science teacher from Colorado made a significant paleontological discovery while volunteering on a fossil dig in North Dakota’s badlands last year. Kent Hups, who was recovering from knee replacement surgery and carefully navigating easier terrain, noticed a large, triangular shape in hardened sandstone that resembled dinosaur toes. Upon measuring the formation, he realized he had uncovered a rare finding: only the third confirmed adult Tyrannosaurus rex footprints ever documented.

The discovery, located within the Hell Creek Formation—a well-known fossil-rich region spanning the Northern Great Plains—consists of a continuous 23-foot (seven-meter) trackway comprising four massive three-toed footprints. This marks the first time a walking trackway of a fully grown T. rex has been identified, providing new insights into the movement and gait of the prehistoric giant.

Paleontologist Thomas Carr of Carthage College in Wisconsin, who was not involved in the excavation, highlighted the significance of the find. He noted that after more than 120 years of fossil exploration in the Hell Creek Formation, this discovery represents an early breakthrough and expressed optimism that more trackways could be uncovered in the future.

Each footprint measures roughly three feet long and two feet wide, with the stride between prints reaching approximately 13 feet. These dimensions allow researchers to better understand how the T. rex, which could weigh up to 10 tons, moved across its environment roughly 66.5 million years ago. The tracks are believed to have been made near an ancient riverbank.

The trackway was uncovered in July 2025 on federal land managed by the U.S. Forest Service near Marmarth, North Dakota, and the findings were published this month in the Journal of Vertebrate Paleontology. When Mr. Hups first spotted the footprints and sent a photo to the excavation team leader, Tyler Lyson of the Denver Museum of Nature and Science, the initial reaction was skepticism. Dr. Lyson noted that natural weathering can often create rock shapes resembling footprints, making early identification difficult.

However, after careful examination of the tracks’ size, the narrow configuration of the toes, and the high concentration of T. rex fossils in the area, Dr. Lyson and his team confirmed the discovery. Before this, only two adult T. rex footprints had been found: one isolated print in Montana and another in New Mexico.

This newly documented trackway not only marks a rare addition to the fossil record but also enhances scientists’ understanding of the locomotion and behavior of one of the most iconic dinosaurs.