Place

Beginning Dinosaur's Fossil Discovery Trail

Quick Facts
Like chapters in a book, the geologic formations (layers) on this tilted rock trail are chapters of ancient environments deposited here over millions of years. While standing behind the Quarry Visitor Center, look at the Frontier Sandstone cliff beside you. High above the trailhead sign and on the cliff, notice the wavy ripple marks within the large dark brown patches. These ripples were created when water moved over sand. If you were hiking here approximately 100 million years ago, you would have been walking along the sandy shores of the Cretaceous Interior Seaway. Cretaceous Atlas of Ancient Life | Geology A vast difference from the high desert environment of today!

On the ground, behind and to the left of the trailhead sign is another notable feature, a huge chocolate-colored rocky sphere known as a concretion. This concretion also has a delightful star-shaped crack that filled in with minerals which crystalized. Concretions are masses of mineral matter embedded in the sandstone. They often form when minerals settling out ground water gather around a nucleus, such as a pebble or shell. Concretions can be any size, but the hefty dimensions of this one (and others here) is due to the presence of large amounts of water from the former seaway. 

While staying on the trail, there are a number of other large concretions in this area How many others can you locate? Hint: There are five others, but some are badly weathered and have broke apart.

As you proceed along the Frontier Formation, you may see animals such as squirrels, marmots, birds, rabbits, snakes, or lizards. NPSpecies- Search for a Park Species List
Keep wildlife wild and yourself safe by observing all creatures from a distance.

Once you reach the end of the Frontier Formation, just around the corner, you'll see how ancient people used the geology here. Petroglyphs were pecked into this rock with tools to make symbols of people, animals or patterns. Pictographs are painted symbols. These were created approximately 1,000 years ago by ancient people archaeologists call the Fremont. Fremont Culture - Dinosaur National Monument (U.S. National Park Service) (nps.gov). Since the Fremont did not have a written language (as did the Egyptians for example, with their hieroglyphs) the exact meaning of the Fremont symbols is unknown.
Help us protect these and all petroglyph sites for future generations by not touching them. 

Hike on to discover the next chapter in our ancient book - the Mowry Shale Formation.

Dinosaur National Monument

Last updated: July 23, 2022