Valley site in Puebla, Mexico, with human occupation from at least 7000 BC. This desert valley, 1800 meters above sea level, has one of the longest continuous sequences in Mesoamerica (ending 1520 AD). The earliest inhabitants were nomadic food-gatherers and hunters. Maize was grown by c 5000 BC, pottery was first made around 2300 BC, and settled village life may go back to the 3rd millennium BC (though it is not well attested before 1800 BC). Incipient agriculture phases gave way to reliance on domesticated foods. From the Pre-Classic period onwards, the valley was not as important as the richer and more fertile areas of Mexico. It was, before the Spanish conquest, a center of Mixteca-Puebla culture. The earliest phase is considered part of the Desert Tradition. The Ajuereado Phase (before 6500 BC) was characterized by small wandering groups engaged in hunting and gathering. In the El Riego Phase (6500-5000 BC) small groups gathered seasonally into larger groups, and grinding tools, weaving, and some plant cultivation occurred. The Coxcatlan Phase (5000-3500 BC) marked the appearance of larger semi-sedentary groups occupying fewer sites and engaged in agriculture. Artifacts include manos and metates and improved basketry. A significant change in settlement pattern occurs in the Abejas Phase (3500-2300 BC) with pit house villages occurring along the river terraces as year-round dwellings. New species of plant food, long obsidian blades, and possibly cotton appeared and there is increased hunting of small game. Pottery, which is a good index to the degree of permanence of a settlement (fragility makes it difficult to transport), was made in the Tehuacán valley by 2300 BC. The later phases (including Purron, 2300-1500 BC) represent a sedentary life, wide use of ceramics, and domestication of the dog.