Nothing was known about the ancient culture sheltered here until archeologists began piecing together the information gleaned from Canyon de Chelly’s many ruins and burials. Their story survived because these people lived in a physical environment that posed a minimal threat to normally fragile remains. Wherever the remains of ancient man occur in the open, building ruins and some objects of stone, bone, and pottery survive, but those of wood and fiber disappear completely. Most of what we know about peoples from the dim past thus comes from materials that have been buried and protected. For the archeologist there are few better sources of information than formal burials, which often contain extensive offerings, and situations like those at Canyon de Chelly and Canyon del Muerto, where sites served as dwelling places for long periods of time and the steady accumulation of refuse buried layers of cultural debris. The extremely arid conditions in the caves of these canyons offered additional protection. The climate here is so dry that human burials are perfectly preserved as natural mummies or desiccated bodies (there being no attempt at artificial preservation by these people), and such fragile buried objects as baskets more than a thousand years old are in good condition. The people who lived at Canyon de Chelly in prehistoric times are today called the Anasazi, a Navajo word meaning “old people.” These people were the ancestors of modern Pueblo Indians, and they lived in the vicinity of northern Arizona and New Mexico, southwestern Colorado, and southeastern Utah from about the beginning of the Christian era to the end of the 13th century. Over most of that period they lived in these canyons. Before they learned to build in the cliffs they located and constructed their houses much differently. But the canyons always sheltered them, and their homes, their dead, and their debris tell us how it was with these people from the beginning to the end of their time here. [Illustration: These bone tools were used to work leather and weave baskets.] THE ANASAZI Early man, a nomadic hunter of big-game animals, came to the Americas from Asia over the Bering Strait some time between 20,000 and 15,000 B.C. Thousands of years later, after the big animals had become extinct, larger bands of hunters and gatherers preyed on game animals of species still living today. Still later, groups began to settle in favorable areas and to grow maize (corn), which reached them from more complex cultures in what is now Mexico. From this time on, the spread and development of prehistoric Indian cultures in the northern Southwest can be traced in increasing detail.