Geology has taught me there are windows to our past everywhere. If you visit our Colorado State Parks, you’ll find windows to very cool geological features.

One of the world’s most rare and significant geologic features can be seen and touched at Trinidad Lake State Park. It is commonly known as the K-T Boundary. (The K stood for a German word for the Cretaceious period and the T represented the Tertiary age. Now it’s known as the Cretaceous–Paleogene boundary.)

Doesn’t matter what you call it, the boundary is incredible. It’s a thin layer of prehistoric dust exposed on an easily accessed rock outcropping in the southern part of the park. Scientists believe the K-T boundary indicates when an asteroid hit Earth near the Yucatan peninsula in Mexico about 65 million years ago.

The impact sent waves of radioactive dust circling the planet, choking out sunlight and inhibiting photosynthesis, leading to the extinction of dinosaurs.

If you’re a fan of dinosaurs, then you know how cool it is to touch the point in time when dinosaurs were wiped out.

Trinidad Lake is also home to actual dinosaur tracks, indicating the area was home to quite a few of the prehistoric creatures. You can see a display on the dino footprints at the Visitor Center.

Lake Pueblo State Park also has a geologic claim to fame: it is one of the best places in North America to see the Graneros, Greenhorn, Carlile and Niobrara rock formations with many important features, like volcanic ash beds and fossils.

The rock layers in the Bridge Creek Limestone Member of the Carlile Shale are so complete that the park is internationally recognized as one of the best places in the world to see the boundary between the Cenomanian and Turonian ages of geologic history.

More than 200 scientific papers have been published about the rock formations and fossils in the park and it was chosen as a prestigious Global Boundary Stratotype Section and Point.

Want more dinosaur footprints? Make tracks to John Martin Reservoir State Park where you can find dinosaur prints dating back 97 million years. The tracks are usually submerged, but they can be seen during periods of low water. Tracks are actually as significant in the study of dinosaurs as bones and fossils. They can be used to map possible migration, home ranges and if they were solitary versus herds.

Geologic events created what is now the Arkansas Headwater Recreation Area, a state park stretching from near Leadville through Buena Vista and Salida to Cañon City.

The events started 325 million years ago, which included uplifts that eroded away when the seas moved inland, a stress in the continental plate that pulled at both sides of the Sawatch uplift until the center broke loose and slid downward, creating a trough that spanned from Leadville to New Mexico.

Volcanoes spewed lava and ash that formed mountains on the eastern side of an uplift, creating the Arkansas River. Glacier episodes scoured the rock and filled the valley with rocks and dirt, affecting the course of the river. The magma from the volcanoes that is below the surface fuels the area’s hot springs.

While we think about geology as a rocky window to the past, these events are still happening. The mountains still rise and erode, but at a rate that keeps the elevations constant. Searching for geological remnants like gems, minerals, fossils or tracks is fun and educational, but please remember, removing items from a state park is illegal and ruins others’ chances to explore.

Darcy Mount graduated from the University of Northern Colorado with a degree in biology. She works as the senior park ranger at Cheyenne Mountain State Park. With questions about Colorado Parks and Wildlife, contact Darcy at

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