Alibates Flint Quarries

Alibates Flint Quarries National Monument is a U.S. National Monument in the State of Texas. For thousands of years, people came to the red bluffs above the Canadian River for flint, vital to their existence. Demand for the high quality, rainbow-hued flint is reflected in the distribution of Alibates Flint through the Great Plains and beyond. Indians of the Ice Age Clovis Culture used Alibates flint for spear points to hunt the Imperial Mammoth before the Great Lakes were formed. The flint usually lies just below the surface at ridge level in a layer up to six feet thick. The quarry pits were not very large, between 5 to 25 feet wide and 4 to 7 feet deep. Many of these quarries were exploited by the Antelope Creek people, of the Panhandle culture, between 1200 and 1450. The stone-slabbed, multi-room 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 made in advance.

• http://en.wikipedia.org/wiki/Alibates Flint Quarries National Monument