From the National Parks Traveller (Kurt Repanshek):
Mary Risser, Dinosaur’s superintendent since 2005, answers the question by referring to the nomenclature of the National Park System.
“What they say is a national park contains a variety of resources and encompasses large land or water areas to provide adequate protection of the resources,” notes the superintendent. “A monument is intended to preserve at least one nationally significant resource. It’s usually smaller than a national park, and it lacks a diversity of attractions.
“So, when you look at the definition, Dinosaur would definitely qualify as a national park. When you think about the resources that we have here, you start with the Douglas Quarry, which is the world’s best window into the Jurassic-era dinosaurs, (and) we’ve just found probably one of the world’s most significant cretaceous area dinosaur quarries right across,” continues Superintendent Risser. “We have two of the West’s premier white-water rivers. … and then we have over 200,000 acres of wilderness. I think Dinosaur has features that you find in all the other national parks in the state (Utah).
“We can trace human history for 10,000 years here. It has the most complete geologic record in the National Park System, even more so than Grand Canyon. So it’s just a spectacular place.”