Alibates Flint Quarries National Monument

Alibates flint is an agatized dolomite, usually banded maroon and white, sometimes blue, brown, red or yellow, and it outcrops along both sides of the Canadian River north of Amarillo. The National Park Service dates its use to mammoth hunters some 13,000 years ago, and people kept working it for thousands of years after. The flint is richest on a 60-acre stretch of mesa top, and more than 736 hand-dug quarry pits remain, each a depression more than six feet across where diggers went a foot or more down to unweathered stone.

Between about 1150 and 1450, Plains Village people, likely ancestors of the Caddo, Pawnee and Wichita, lived in stone-walled villages along the river and worked the flint into blades and blanks for trade. Alibates tools turned up across the Great Plains and as far as Canada and Mexico, and the villagers took in Pueblo pottery from the Rio Grande, obsidian from the Jemez Mountains, pipestone from Minnesota and shells from the Pacific. The monument, set aside in 1965, was the first national monument in Texas.

The quarries can be seen only with a ranger. Tours leave the visitor center at 10 a.m., or 9 a.m. in summer, by reservation, and climb about 170 feet over two miles in roughly two hours. Wear long pants and closed-toe shoes, and expect cancellations in bad weather. The visitor center, open daily, has exhibits on the flint and its trade. Collecting, digging and metal detecting are illegal.