One good example is the site of what is now the Mygatt-Moore Quarry near Fruita, Colorado. It was discovered on a late March hike in 1981 by Grand Junction, Colorado, residents Pete and Marilyn Mygatt and J.D. and Vanetta Moore. They were amateur rock and fossil hunters who had “cabin fever” that day and decided to go for a hike near the Utah border. During a lunch break, Pete Mygatt noticed a rock and picked it up. It split apart, revealing a partial tail vertebra of what was later identified as an Apatosaurus. This site is now named the Mygatt-Moore Quarry, and has yielded eight species of dinosaurs, including Mymoorapelta, a small armored dinosaur, and the first ankylosaur from the Jurassic period found in North America.

Another example is Rob Gaston, a local Fruita, Colorado, artist who found some of the earliest dinosaur tracks in western Colorado. His discoveries led to the discovery of the Gaston Quarry, where the Utahraptor was subsequently found.

Still another find: Christopher Wolfe, an eight-year-old third grader from Phoenix, Arizona, discovered the remains of the oldest known horned dinosaur during a trip to western New Mexico. As he climbed up a hill, he was attracted to a blackish purple object on the ground, which turned out to be a fossilized piece of the small horn that protected the dinosaur’s eye. The rest of the fossilized remains included jaw parts, teeth, brain case, and other pieces. The dinosaur was approximately 90 million years old—the oldest known horned dinosaur to that date—and was named Zuniceratops christopheri after its discoverer.