The 100-foot-long building, known as a "great house," may have been inhabited by several elite Pueblo families at any one time, according Stephen Lekson of the University of Colorado Museum. CU-Boulder students are returning June 2 for a second season of excavations at the site, which is linked to the mighty Chaco culture that dominated much of the Southwest roughly a thousand years ago.
Known as the Bluff Great House, the Anasazi site also harbors the remains of a great kiva and series of prehistoric roads, said Lekson. The 7.5-acre site is located in the Four Corners region about 30 miles from the Colorado border.
The project was undertaken by CU-Boulder in cooperation with the Southwest Heritage Foundation -- a nonprofit corporation founded to support the project -- and Abajo Archaeology, a private contract firm in Bluff. An $18,000 grant from the National Geographic Society will fund the work this field season, said Lekson.
The project is co-directed by the husband-and-wife team of Lekson and CU-Boulder assistant anthropology Professor Catherine Cameron.
"We now have an enormously better idea of what the Great House was like," said Lekson. "The earliest construction appears to be much more Chacoan than subsequent construction events."
Although not as carefully crafted, the Bluff Great House is architecturally similar to great houses at Chaco Canyon, a series of Pueblo ruins in northern New Mexico that dominated the culture of the region from A.D. 900 to 1150. The Bluff site appears to have been one of the most distant "outposts" under Chacoan influence.
The archaeology field team includes 13 CU-Boulder students and four crew leaders who will continue excavating portions of the great house, a great kiva, trash middens and a series of berms circling the site that appear to mark ancient roadways.
The students will rotate around the excavations weekly and will spend time each week studying ceramics and stone tools with Abajo Archaeology professionals.
"We want to make sure our students get dipped into a little bit of everything in terms of experience," said Lekson, who noted some students also may work with the U.S. Bureau of Land Management on a mapping survey of area Pueblo sites.
The 1996 team collected thousands of pottery sherds from the debris-filled berms and middens surrounding the Bluff site that are helping to determine when it was occupied and learn more about the ancient people. The pottery fragments at Bluff appear to date from about A.D. 600. to 1300, and at least one partial potsherd suggests "stylistic emulation," indicating local people were copying pottery styles from Chaco Canyon, said Cameron.
Animal bones collected from the great house and middens in 1996 indicate the most commonly hunted animals were cottontails, jack rabbits, deer and turkey.
Lekson also hopes to investigate whether a prehistoric road leading southeast from the great house toward Chaco Canyon 125 miles away passes by Teec Nos Pos, a northeast New Mexico Navajo community adjacent to another great house ruin.
One major question is whether "priests" from Chaco traveled to places like Bluff to help establish outlying sites, or if Bluff inhabitants were so impressed by the powerful Chaco culture they decided to replicate it locally, Cameron said. Although the Chaco influence stretched over some 40,000 square miles of the Southwest -- an area about the size of Ohio -- during its zenith in the early 1100s the culture abruptly disappeared by about 1150. Archaeologists have theorized the collapse may have been caused by drought, warfare or internal political strife.
A 1996 test pit indicates the Bluff site's great kiva originally may have been built with upright stone slabs, then later remodeled into a smaller structure with masonry lining the walls, she said. The researchers hope to date the building episodes of the subterranean religious structure and great house this summer.
As part of the field school, CU-Boulder will bring in other archaeologists for guest lectures and the students will make weekend field trips to other Pueblo archaeological sites in the Southwest, including Chaco Canyon.
The Bluff Great House appears to have contained several dozen rooms and a large community storage area, said Lekson. In contrast, Pueblo Bonito, a great house in Chaco Canyon, was five stories tall and contained 800 rooms. One unanswered question is whether great houses like Bluff were "dropped into" existing communities or built to bring local people together into a cohesive group, he said.