• Jasper Forest is magical in twilight, particularly the logs on stone pedestals

    Petrified Forest

    National Park Arizona

Agate House

walls constructed of petrified wood

The petrified wood walls of Agate House

NPS/Marge Post

The ancestors of the modern Pueblo people used petrified wood for a variety of purposes including tools such as projectile points, knives, and scrapers. Agate House demonstrates another innovative use of petrified wood, as a building material for masonry structures. The ancestral Pueblo inhabitants constructed this small, eight-room pueblo about 900 years ago in a location near to both agricultural fields and petrified wood deposits. The size of the structure and time necessary to build and maintain it indicates that this was not a temporary residence or field house, but more likely a year-round residential structure for a family unit. Others have suggested that this structure served solely ceremonial purposes and did not serve as the residence for a family group. Like most structures from this time period it likely remained in use for less than a generation or thirty years.

It is estimated that Agate House was constructed and occupied between 900 and 1200 AD. This determination is based on the ceramic assemblage discovered at the time of excavation, including coiled utility ware and various black-on-white painted ceramics with a few examples of black-on-red. Most of the pottery appears to be associated with ancestral Puebloan people (i.e. Anasazi), although some of the pottery has southern origins, perhaps associated with the Mogollon.
 
Agate House

Agate House

NPS

Reconstructed in the 1930s, Agate House is located on top of a small hill within the Rainbow Forest. Some questions remain about the accuracy of this reconstruction, but it still enables us to envision the daily lives of the ancestral Puebloans.

Would you like to visit Agate House? The Agate House Trail runs 1.25 mile from the Rainbow Forest Museum parking lot. A shade shelter at the junction of these two trails offers the only shade as you cross the badlands and petrified wood scattered landscape. Water, sun protection, and comfortable shoes are strongly recommended.

This dwelling is fragile.Do not sit stand or lean on the walls.
 
Agate House Interior

Agate House Interior, including a metate

NPS

Agate House and the Civilian Conservation Crops.
From 1933-1934, CCC workers recontructed Agate House under the eye of archeologist Cornelius Burton Cosgrove.

In 1933-34, Cosgrove documented the the existence of the following item in Room 7: "Against the east wall, near the center of the room, was a stone bench 1'0" x 1'9" and 1'9" high.It was made up of two large worked sandstone slabs on top and supported by smaller broken pieces underneath to make it level..."Likewise in Room 2, they discovered a 12"x16"x6" slab lined fire pit against the center of the south wall.Neither of these elements currently exist.
 
1934 CCC Agate House

CCC working on reconstructing Agate House, 1934

NPS Historic Photo

C.B. Cosgrove prepared a "Report on Excavation, Repair, and Restoration of Agate House and Other Sites" in 1933-34 (copied by L.B. Henderson in October 1963). Working for the Laboratory of Anthropology at the Museum of New Mexico, Cosgrove oversaw the excavation and reconstruction of Agate House in the winter of 1933-34 using local Civilian Conservation Corps labor. In his report, Cosgrove says no previous work had been conducted at Agate House before 1933, although its location had been known for "several years."

His excavation report began with the CCC removing all of the loose surface petrified wood, which they set aside to be later used in reconstructing the walls. Under the surface materials, they discovered most of the foundations "were fairly good and easy to follow." He reported the walls to be one foot thick and the floors of the pueblo averaged 8-18 inches below the existing grade. Firepits were discovered in two rooms. Excavation began in rooms 2 and 3, continuing with 4, 5, 6, and 1. Rooms 7 and 8 were the last to be excavated.

According to the 1933-34 site excavation report, Agate House was constructed using medium to large pieces of petrified wood, which were presumably carried to the top of the knoll. The walls were originally constructed of petrified wood held in place by mud mortar and chinked with smaller pieces of petrified wood.
 
Agate House was listed on the National Register of Historic Places in 1975 under Criterion D for its local significance as an archeological site, although the property should have also been evaluated for local significance under Criterion A due to its association with the Civilian Conservation Corps.

The significance of the property was defined in the National Register nomination as follows: "1) As a pueblo-type structure, it offers a contrast to Puerco Ruin and to other small pueblo ruins known for Park localities. It is typical in layout of late Pueblo II period family settlements which were often several rooms. 2) While perhaps typical is the layout, room features, placement on a low ridge, and general size, Agate House is of course striking in appearance. Throughout the Park, much of the actual room construction was done with locally occurring sandstone slabs and blocks. 3) Agate House indicates continuing southern contacts and influences during the 10th and 11th centuries, especially within sites of the Rainbow Forest District. As some of the pottery found was common to the Forestdale and Showlow areas to the south, the Mogollon culture of these areas was an important and continuing influence on the inhabitants of the present-day park region."

Did You Know?

closeup of colorful agatized petrified wood

Petrified wood at Petrified Forest National Park is almost solid quartz, weighing in at 168 pounds per cubic foot. It's so hard, you can only cut it with a diamond tipped saw! More...