Monument Rocks, Kansas

Monument Rocks, also called the Chalk Pyramids, are a series of large chalk formations south of Oakley in Gove County, Kansas, in the Smoky Hills region, rich in fossils. The chalk accumulated during the Cretaceous period roughly 80 million years ago, when the Western Interior Seaway covered the area and temporarily divided North America into two landmasses. The formations rise up to about 70 feet, or 21 meters, taking varied shapes that include buttes and natural arches, on a landscape sitting around 2,631 feet above sea level. In 1968 Monument Rocks became the first site in Kansas designated a National Natural Landmark by the U.S. Department of the Interior, and in 2008 it was named one of the Eight Wonders of Kansas alongside the nearby Castle Rock formation. This entity documents Monument Rocks specifically as a geological formation.