The Dinosaur Quarry. Dinosaur National Monument, Colorado-Utah

Approaching the remote corner of the American West, the jagged silhouette of Split Mountain gives way to a valley of tilted sandstone, colorful shale, and sparse sagebrush. The visitor center at Dinosaur National Monument sits beside the famed Dinosaur Ledge, where a massive quarry holds one of the richest deposits of Jurassic fossils on the planet. A short walk from the parking lot reveals the “rainbow beds,” layers of pink, red, green and gray stone that frame the ancient story waiting to be uncovered.

The exposed rocks belong to the Morrison Formation, dating back about 150 million years, and they contain bones from chicken‑sized theropods to towering, long‑necked giants. By studying teeth, claws and limb shapes, scientists can tell which creatures were swift carnivores and which were massive herbivores that roamed ancient swamps. Early explorers in the late 1700s first uncovered isolated fragments, sparking a scientific dialogue that still drives the quarry’s research today.