First Fossil Discovery in 100 Years at Dinosaur Monument

Sometimes the best discoveries happen when you're just trying to fix a parking lot.

Workers at Dinosaur National Monument on the Colorado-Utah border made history in September 2025 when they stumbled upon dinosaur fossils during a routine construction project. These are the first fossils excavated at the famous monument in more than 100 years.

The bones likely belong to a Diplodocus longus, a gentle giant herbivore with a long neck that roamed the area 150 million years ago during the Late Jurassic period. Park staff had hoped they might find something special since the old parking lot was built on top of discarded rock and soil from the original excavations that ended in 1924.

When monitors spotted fossils in an exposed sandstone wall on September 16, construction stopped immediately. Over the next two months, park staff teamed up with volunteers, construction crews, and a Utah Conservation Corps team to carefully extract 3,000 pounds of fossils and rock.

The team has only recovered about 20 feet of the sauropod so far. Since these dinosaurs typically stretched to 80 feet long, there's much more waiting to be discovered when excavations resume in the spring after winter weather clears.

The Ripple Effect

This discovery breathes new life into a site already famous for fossils. Visitors can now watch scientists prepare some of the newly found fossils at the nearby Utah Field House of Natural History State Park Museum. Other pieces are already on display at the monument's Quarry Exhibit Hall, nicknamed the "Wall of Bones," which showcases an impressive 1,500 dinosaur fossils.

The timing couldn't be better for dinosaur enthusiasts in the region. Just last year, the Denver Museum of Nature and Science announced another remarkable find when workers drilling for a geothermal energy project discovered a 67.5-million-year-old dinosaur vertebra 763 feet underground. That fossil became the deepest and oldest dinosaur bone ever found within Denver city limits.

These accidental discoveries prove that ancient treasures still hide beneath our feet, waiting patiently to share their stories with a new generation of scientists and curious minds.