Monument Rocks, In Color
Monument Rocks in western Kansas are bathed in the soft light of a sun that has set. The towering formations, some 70 feet tall, date back some 80 million years, when a large, shallow sea separated what now are the East and West coasts of the United States. The Niobrara chalk is rich in fossils from the former sea. In 1968 the National Park Service designated Monument Rocks, in the Smoky Hill River valley south of Oakley, as the first National Natural Landmark in Kansas.