Between AD 900 and 1150, Chaco Canyon was a major center of culture for the Ancient Pueblo Peoples. Chacoans quarried sandstone blocks and hauled timber from great distances, assembling 15 major complexes which remained the largest buildings in North America until the 19th century. Evidence of archaeoastronomy at Chaco has been proposed, with the Sun Dagger petroglyph at Fajada Butte a popular example. Many Chacoan buildings may have been aligned to capture the solar and lunar cycles, requiring generations of astronomical observations and centuries of skillfully coordinated construction. Climate change is thought to have led to the emigration of Chacoans and the eventual abandonment of the canyon, beginning with a 50-year drought in 1130.... More • http://en.wikipedia. ... rical_Park View • Books • Images • Videos • Search Related • Buildings • America • Archaeology • Indians • Middle Ages • Native American • New Mexico • Unesco • USA • 10th Century BC • All Events • North America