NPS/Marge Post

Agate House is one of many dwelling sites found in the park.

The ancient people may not have recognized the petrified wood as fossil tree pieces, but they did have stories to explain this abundant resource. The Paiute of southern Utah believed the petrified logs to be the arrow shafts of their thunder god, Shinuav. The Navajo believed that the logs were the bones of the monster Yietso, the Great Giant their ancestors slew when they first arrived in the Southwest.

Archeologists use building sites, including the architectural styles, methods, and materials, and associated artifacts, such as pottery and tools, to learn about past human use of the Petrified Forest. Styles evolve and change as ideas spread from place to place. By studying patterns of movement in association with patterns of change, scientists learn about the culture of the prehistoric inhabitants.

NPS/Marge Post

Petrified wood was used for stone tools such as this projectile point.

Early inhabitants used mostly local materials for dwellings, pottery, tools, clothing, and food, but traded for exotic materials such as turquoise, coral, and shell. Petrified wood may have been an excellent trade item, as evidenced by petrified wood tools found in other areas of the Southwest.

Prehistoric peoples were directly influenced by environmental changes. Ancient storage facilities have been found at some of the habitation sites in the park, indicating that during years when crops were good, they may have stored surpluses just as modern Puebloan people do today.

During the thirteenth century a series of droughts devastated the Southwest. Vegetation decreased and animals died. Farming became impossible in many areas. People migrated or perished. At Petrified Forest it appears that inhabitants congregated into larger pueblos in areas where farming was still a possibility, such as along the Puerco River. By developing new farming methods, new styles of construction, and new customs the people of Puerco Pueblo survived the drought years, only to be forced out by additional environmental change.

NPS/Marge Post

Pot sherds are an important resource at Petrified Forest National Park.

Even though several artifacts found in the park represent a human presence in the area over 10,000 years ago, the oldest habitation site may have been occupied just prior to A.D. 500 during the Basketmaker II period. The village had 25 round to oval pithouses scattered about a mesa top, with long, narrow east-facing entryways. They had been dug into the ground and lined with thin slabs of sandstone set on edge. The upper portion of the walls and roof may have been made of brush and mud supported by juniper logs.

Artifacts found at this site include grinding stones, hammerstones, pipes, blades, scrapers, and projectile points. Most of the stone artifacts were made of local materials such as sandstone, chert, and petrified wood. Pottery found includes bowls, jars, ladles, and a vessel in the shape of a duck. Most of the pottery was gray-brown or tan to light red and was left undecorated. Pottery is an important find at such an old site.

Archeologists believe this site was only occupied for part of the year, most likely only during the summer growing season.

NPS/Marge Post

Petroglyphs help archeologists understand the ancestral Puebloan people.

A somewhat later site indicates cultural change. Located on the floor of a broad valley, a Basketmaker III site, occupied from about A.D. 500 to A.D. 800, had 15 separate units scattered over almost one-half mile square. Within each unit, the pithouses were deeper and included several semi-subterranean storage structures, usually arranged in a crescent behind the pithouses. One of the houses excavated had mud-plastered walls while another had only the sandstone slab walls as in the Basketmaker II site. Other innovations were small storage pits in the floor and a ventilator shaft.

Cultural change is also shown in the styles of pottery, jewelry, and tools found. The style of projectile points changed and some of the pottery was decorated. Pottery from the Mogollon people to the south and shells of marine origin indicates that trade occurred. Artifacts such as shell and bone awls, needles, pendants, beads, and bracelets were also found.

Human burial sites were found in the village, with evidence that the people had ceremonial burial practices. Even without evidence of any source of water other than summer rainfall, farming must have been productive enough to support a year-round occupation. Low stone windbreaks, farmland on hillsides, the large food-storage structures, and the close-knit organization of the village support occupation all year.