New dinosaur fossils have been discovered at Dinosaur National Monument, leading to the first dig in more than 100 years, officials revealed Friday.
The National Park Service said construction of a parking lot was underway in September near the Quarry Exhibit Hall on the Utah side when the dinosaur fossils were discovered. Dinosaur National Monument is located on the Colorado-Utah border, about 300 miles west of Denver.
Some of the dinosaur-bearing sandstone was exposed when the asphalt was removed Sept. 16 by workers. Construction was immediately halted to allow paleontologists to evaluate and excavate the fossils.
“The fossils belong to a large, long-necked dinosaur, very similar to Diplodocus, which is common in this bone deposit,” the NPS said in a statement.
About 3,000 pounds of fossils and rocks were removed during the dig between mid-September and mid-October, the NPS said. The fossils are being cleaned and studied at the Utah Field House National Park Museum of Natural History in Vernal, Utah.
National Park Service 
According to the NPS, the bonebed area has not been excavated for fossils since initial excavations at the site ended in 1924. In the meantime, the parking lot and road improvement construction project was completed once excavations were completed.
Research published last October suggests that dinosaur populations were still booming in North America before an asteroid hit Earth 66 million years ago.
In January 2025, almost A 70 million year old dinosaur fossil was discovered during a parking lot project at the Denver Museum of Nature and Science. It is the oldest dinosaur fossil ever discovered within Denver city limits.
“This fossil dates from a time just before the mass extinction that wiped out the dinosaurs, and it provides a rare window into the ecosystem that once existed just beneath present-day Denver,” the museum’s curator of geology, James Hagadorn, said at the time.
