Garden of the Gods has been many things: a tropical haven; an inland sea; a field of sand dunes; and, even a vast swampy floodplain. Dinosaurs once grazed on the ferns and other tropical plants. Sea serpents swam in shallow waters and mammoths trudged through deep snow in May. The rocks reveal secrets of ancient environments to those who know their language.
A billion years ago, molten rock cooled to create Pikes Peak granite and the Ancestral Rockies. Approximately 310-270 million years ago, the ancestral Rockies were worn down bit by bit. About 250 million years ago, Garden of the Gods had sandy beaches and an inland sea. The 300 foot orange sandstone rocks in the Garden of the Gods were once sand dunes. They may have looked similar to those at the Great Sand Dunes National Monument in southern Colorado. An inland sea once again covered Colorado about 225 million years ago. Around 155 million years ago (the Jurassic period), dinosaurs roamed the Garden of the Gods.
About 65 million years ago, there was an intense period of mountain building caused by the old Pacific plate slamming into the North American plate. As the Front Range Mountains rose, the overlying sedimentary rocks were bent upward. Over time, the softer rocks eroded and valleys were created leaving harder rocks standing as the tall ridges in the Park. These distinctive formations draw millions of people annually who come to enjoy the beauty of the Park and learn the secrets of this unique place.