Dinosaurs walked the Earth millions of years ago, but they left quite the impression.

A Utah resident uncovered hundreds of dinosaur footprints near the city of Moab in 2009. The site has been kept secret until now.

Scientists from the University of Colorado and the Bureau of Land Management began excavations last year. Volunteers are helping to prepare the site for a planned October opening to the public.

"It's tracks of the past, really, and it's very cool to be trying to preserve that information," Allyson Mathis, a science writer and volunteer, told KSL in Utah.

The great beasts made their marks 125 million years ago during the Cretaceous period. Volunteers have dusted off more than 200 footprints in an area no bigger than a football field. In one case there were "17 consecutive prints from the same animal," according to volunteer Lee Shenton.

Some of the tracks belong to species with little to no bone evidence.

"It helps kind of fill in these gaps about these animals that we don't know much about, that we know were here, but we just don't find their bones," said Rebecca Hunt-Foster, a paleontologist for the Bureau of Land Management.

Scientists from the University of Colorado and the BLM have helped identify prints from an ancient crocodile and a three-toed meat eater. The crocodile left a tail mark in the hardened mud and the meat eater identifies closely with a Utahraptor.

"That's the claw that had the big scary claw on it, like in 'Jurassic Park,'" Hunt-Foster said, referring to the 1993 Steven Spielberg film.

Scientists will further document the "exceptionally well-preserved" tracks using 3-D photography, according to KSL.

"And then we'll be able to replicate any of the tracks, should they ever be damaged or destroyed," Hunt-Foster said. "And also people will be able to study them without doing damage to the actual surface."

To make access to the site easier, the BLM is raising funds to build a trail to the dinosaur prints.