For thousands of years, people came to the red bluffs above the Canadian River for flint, vital to their existence.

Native Americans of the Ice Age Clovis culture used Alibates flint for spear points to hunt the Columbian mammoth before the Great Lakes were formed.

The flint usually lies just below the surface at ridge level in a layer up to 6 ft thick.

The stone-slabbed, multiroom houses built by the Antelope Creek people have long been of interest to the public and studied by archaeologists.

Today, this area is protected by the U.S. National Park Service and can only be viewed by ranger-led guided tours, which must be reserved in advance.