If you could take a shovel and dig deep beneath your feet, you'd hit a jackpot of stories. Sometimes, the odor of sulfur hangs in the air-left over from the marshes that turned into low-grade coal and the swampy, oozy mud that swallowed whole forests and dino bones. Rocks here glitter, holding pieces of the past: light-grey claystone, rough brown sandstone, sparkling minerals, and volcanic shards. You’re standing atop rivers of rock that once held mighty dinosaurs like Triceratops and duck-billed hadrosaurs, making you a neighbor to creatures that looked like they stomped out of a child’s imagination. Their gigantic bones-now fossils-hide out in the lower layers, proof that Colorado was the neighborhood for these thunder lizards.
But then, things changed-fast. About 66 million years ago, a truly out-of-this-world event: a giant asteroid crashed into Earth, wiping out most of the dinosaurs. That dramatic boundary-the Cretaceous-Paleogene event-is written in stone right here in the Denver Formation, especially on South Table Mountain nearby. You might want to imagine the sky darkening, ash falling, and silence spreading where once lived roaring, squawking, and splashing.
After the dinosaurs checked out, early mammals and turtles made this their home. Plants grew and died, leaving fossil leaves pressed like secrets into the rocks. Lava flowed from nearby Table Mountain volcanoes, bubbling up and burying the land in molten rock. Inside that lava, hidden crystals and rare minerals sleep-zeolites with wild names like thomsonite and analcime. And nestled in these rocks are aquifers, underground rivers still supplying water to Denver today.
So as you finish this journey, take a deep breath and let it sink in: you’re walking on history, hundreds of feet thick, full of lost worlds and explosive change. Denver’s foundation is more than just city blocks-it’s an epic saga written in stone, waiting for explorers like you to listen. And lucky for you, dinosaurs can no longer chase tour guides-though I can’t promise I won’t make a quick getaway if I see one!
Curious about the stratigraphy, thickness and lithology or the age and paleontology? Don't hesitate to reach out in the chat section for additional details.
