Vail Daily column: Dig into fun this fall with fossils |

Vail Daily column: Dig into fun this fall with fossils

There is a newfound meaning and appreciation for how colorful Colorado truly is when looking into its geologic record. In fact, this land is so beautifully sprinkled with fossils that museums around the world have been housing them for nearly 150 years. Whether you’re an amateur like myself or the professional paleontologist, there is still a lot left to discover on this never-ending fossil frontier.

Here in Colorado, most of our fossils have been found in sedimentary rocks. These are rocks that form when sediment is deposited, compressed under layers and cemented together via minerals. If an animal or plant dies and is buried quickly under sediment, like at the bottom of a lake, then fossilization can ensue. The soft tissues decay while the hard bony parts remain, continually being buried under more sediment. Once buried deep under many rock layers, groundwater seeps into the remains, and minerals in the water fill empty spaces within, forming crystals. The crystalized minerals cause the remains to harden along with the surrounding sedimentary rock. These perfect conditions lead to the most common type of fossilization known as permineralization. Other fossils may be made from carbonization, replacement or molds and casts.


Fossils are typically characterized as either body or trace. Body fossils are the actual remains of a living plant or animal, like bones, shells and teeth. Trace fossils are indicators of ancient life and behaviors, such as footprints, nests and tooth marks. Both are key in understanding what this land looked liked millions of years ago, what animals walked on the very ground we stand and which plants dominated the ancient environments. Every new fossil found is an irreplaceable piece to the puzzle of Earth’s history.


Reveal Colorado’s colorful nature for yourself and go fossil exploring around the state this fall! Locally, you’ll find treasures that reveal this land was once a tropical sea between the Ancestral Rocky Mountains 300 million years ago. Near the town of McCoy, you can find fossil beds full of brachiopods, gastropods, horn corals, crinoids and shark teeth that reveal the diverse marine environment of the past. After the Ancestral Rockies eroded away, fossils once again show that another seaway flooded Colorado roughly 100 million years ago. Near the town of Kremmling we find this evidence, with the highest concentration of ammonites, large squid like creatures living inside a coil-shaped shell, in the world! You can hike around both sites, as they are located on BLM land, but leave fossils where they are to ensure preservation and enjoyment by others.

Another ancient landscape can be found at the Florissant Fossil Beds National Monument. Here you’ll see massive petrified stumps of redwood trees, up to 1,500 different kinds of insects and spiders, fish, birds, leaves and seeds dating back 34 million years. During this time, the area near Florissant was semitropical and warm with a large lake, mountain streams, ferns, conifers and erupting volcanoes. It’s no surprise why the National Park Service protected this prized gem after learning how unique, rich and diverse this fossil locality is.


The extinct landscapes of Colorado wouldn’t be as colorful without the help of dinosaurs who appeared about 230 million years ago. Many sites around the state feature jaw dropping displays, trails and quarries of extraordinary dinosaur fossils. One of the most notable places is Dinosaur National Monument, where the state’s very first fossil was found in 1870. Dinosaur Ridge near Morrison is another must-go site. Discoveries made here are said to have sparked the dinosaur gold rush. Other sites abound. Canon City has an active research site — the Garden Park Fossil Area, with trails and interpretive displays, is perfect for self-exploration. You can also literally walk in the footprints of a dinosaur at one of the world’s largest fossil track ways in Picketwire Canyonlands.

Other notable sites worth mentioning are the Dinosaur Journey Museum, Rocky Mountain Dinosaur Resource Center, Mclnnis Canyons National Conservation Area, Riggs Hill and, of course, the Denver Museum of Nature and Science. Start your journey into the rich geologic history of Colorado with a visit to one of these great fossil locales.

Morgan Ballinger is a naturalist at Waking Mountain Science Center who loves all things wild and weird about our natural world.

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