Garden of the Gods, a public park in Colorado Springs, Colorado, spanning 1,341.3 acres, showcases an array of towering red rock formations. Designated a National Natural Landmark in 1971, its striking features invite curiosity about the powerful forces that shaped this iconic site over vast spans of time.
Ancient Sediments and Their Origins
The story of Garden of the Gods begins with the slow accumulation of ancient sediments over hundreds of millions of years. This region was once covered by inland seas, winding rivers, and expansive floodplains. These deposited layers of sand, gravel, and mud, which compacted over eons to form the distinct sedimentary rocks seen today. All of the rock formations within the park are sedimentary in origin, initially laid down in horizontal layers.
The Fountain Formation, forming approximately 320 to 300 million years ago, is prominent. This formation consists of sandstones, conglomerates, and mudstones, derived from the erosion of the ancient Ancestral Rocky Mountains. Its reddish hue comes from iron oxides, and it can reach thicknesses exceeding 4,500 feet. Landmarks like Balanced Rock and the Three Graces are composed of this ancient material.
Another significant rock layer is the Lyons Sandstone, deposited between 300 and 260 million years ago. This sandstone formed in an arid, dune-filled environment. It forms many of the park’s red and white outcrops, including North Gateway Rock and South Gateway Rock. Further layers, like the Lykins Formation, composed of shale, dolomite, and limestone, indicate past tidal environments.
The Forces of Uplift and Tilting
After millions of years of horizontal sediment deposition, geological forces reshaped the landscape. Roughly 70 to 40 million years ago, the Laramide Orogeny occurred. This period of tectonic activity involved continental plates colliding, uplifting the Front Range of the Rocky Mountains and profoundly affecting the Garden of the Gods area.
This uplift pushed the deeply buried sedimentary rock layers upward from their horizontal positions. The forces tilted these formerly flat layers almost vertically, creating the dramatic angles observed in the park today. Some rock beds were pushed beyond vertical. This process also formed the Rampart Range Fault, which runs through the park.
The Rampart Range Fault and other fractures resulted in the displacement and fracturing of rock layers. This faulting contributes to the complex arrangement of the park’s formations, where some rock sections are noticeably offset from others. The pressure and movement transformed the flat sediments into the steeply angled structures that define the Garden of the Gods.
Erosion’s Artistic Hand
Once the deeply buried and tilted rock layers were exposed to the Earth’s surface, the continuous processes of erosion began to sculpt them into their current iconic forms. Wind, water from rain and rivers, and the expansion and contraction of ice (frost wedging) have all played significant roles in this ongoing transformation. These natural agents gradually wore away the rock, but not uniformly.
Differential erosion is a key process at Garden of the Gods; softer rock layers erode more quickly than harder, more resistant ones. This selective removal of material left the more durable rock standing tall, forming the distinctive spires, fins, and balanced rocks that characterize the park. The interplay of these varying rock resistances creates the dramatic and unique shapes seen throughout the landscape.
Over thousands of years, these erosional forces have continued to refine the landscape, carving out valleys and accentuating the prominent rock formations. The effects of glaciation during the Pleistocene Ice Age also contributed to the shaping of the present-day rock formations. This ongoing natural artwork ensures that the Garden of the Gods remains a dynamic and ever-changing display of geological processes.