Archaeologists Ellen Brennen crouched in the relentless sun, meticulously uncovering the curious, two-chambered hearth in the floor of a sunken, circular room built 1,000 years ago in the mysterious depths of the Grand Canyon.
She worked with exquisite care, filling bags with dirt from the hearth. Each bag held tiny traces of pollen, plant remains and animal bones that offered clues to how ancient people made their living on the flood-prone shores of the Colorado River and perhaps why they fled this gash in the earth in the 1300s.
A photographer from National Geographic entered the excavation site carefully and looked around at the archaeologists with kneepads and goggles to protect them from the frequent sandstorms toiling on the floor of the circular room.
“Cool,” said the photographer. “You found a kiva.”
Brennen, who had aimed her whole life at snagging her dream job as a National Park Service archaeologist in the Grand Canyon, looked up, surprised, abashed — and maybe a little irritated.
“We all thought it was a kiva,” she told a rapt audience of about 35 people recently at a meeting of the Rim Country Archaeological Society at the Payson Senior Center, “but we didn’t want to say what it was.”
The discovery of the ceremonial kiva suggested the people who lived for centuries in the depths of the Grand Canyon were linked culturally to the Ancestral Puebloans, whose magnificent ruins include the cliff houses of Mesa Verde in Colorado and the gigantic, ceremonial sprawl of Chaco Canyon in New Mexico.
The kiva also provided support for Hopi traditions that suggest that they are descended from people who farmed corn, beans and squash in sandy bends of the Colorado River for thousands of years before abandoning the canyon shortly before the arrival of the first Spaniards.
Brennen offered a fascinating glimpse of a recent, three-year series of excavations of nine different archaeological sites in the Grand Canyon. Sites buried beneath sand dunes and silt for a thousand years have in recent years been exposed and sometimes washed away by the river, thanks to the construction of Glen Canyon Dam that robbed the river of most of its sediment.
Frigid water released from the bottom of Lake Powell has dramatically increased erosion in the upper reaches of the canyon. Many beaches and backwaters have disappeared, without the big, muddy floods to deposit new layers of silt now piling up on the bottom of Lake Powell.
So archaeologists and volunteers rafted down the canyon and set up camp in some of the rare areas where the canyon opens up enough to form deltas and broad bends where those ancient farmers had enough soil and enough protection from floods to farm their crops.
They spent months building check dams to prevent arroyos from cutting into ruins perched on hillsides and rock walls to protect eroding sites from the river.
They also unearthed and catalogued whole villages, seeking to piece together an ancient civilization before it washed away.
Human beings have made use of the canyon for thousands of years, dating back at least 10,000 years to the last Ice Age. Then, hunters fashioned distinctive stone spear points to slay giant ground sloths, mammoths, camels and even short-faced bears — which would dwarf a modern grizzly.
Those big game hunters gave way to nomadic hunter-gatherers who made sandals of yucca fibers, invented an ingenious handle for a throwing spear, built great roasting pits for agave and created rock art images, but left few structures. They also crafted 4,000-year-old figures of animals ingeniously fashioned from willow twigs.
But the digs Brennen talked about focused on farming villages built between A.D. 400 and A.D. 1250. She noted that these people learned to make pottery, which made it possible to cook beans. This proved essential in the shift to an agricultural lifestyle, since growing the beans restored nitrogen to the soil sucked out of it by corn.
“Pottery and beans go hand-in-hand,” said Brennen. “You need pottery to cook beans, which allowed them to take advantage of the corn/bean/squash system to make a complete diet.”
The archaeologists also discovered evidence these tough, resilient farmers grew cotton, probably imported originally from the civilizations of Meso-America like the Mayan.
So for nearly 1,000 years, these farmers thrived in the Grand Canyon, building stone villages generally above flood high water marks, but relying on the river to replenish the soils of their fields. One protected sequence revealed a 6,500-year-long record of river deposits, including 25 major floods. Many of the dwellings showed evidence they’d been repeatedly flooded, then repaired.
The discovery of the kiva at one of the sites shed light on a longstanding debate about the cultural relationships between the people in the canyon and the contending cultures scattered across the Southwest.
The Hopi still build kivas, where men gather to conduct ceremonies and seek a connection to the spiritual world. Archaeologists have long used kivas to make cultural connections and to chart changes over time.
The dig uncovered evidence that perhaps different cultures occupied different stretches of the river. Some settlements appear related to the Ancestral Puebloans — formerly referred to as the Anasazi. Others seem more closely related to the Havasupai, who still live in the canyon.
The seemingly abrupt abandonment of the canyon after nearly 1,000 years of settlement remains a mystery, with tantalizing clues revealed with each major dig.
Many archaeologists had originally suggested drought, especially after gathering evidence that sometimes the Colorado River all but dried up deep in the canyon.
“New evidence points to a cooling trend,” said Brennen. “As it got colder it became harder to grow corn and they had to move. Also, they may have over-utilized the land and depleted the soil. They lived on such a knife edge.”
She noted that another study of the ruins in the Navajo National Monument concluded that the Ancestral Puebloans may have abandoned settlements when the population grew too small to sustain rituals and religious societies.
After three years of digging, the archaeologists carefully shoveled sand back over the ruins they had so meticulously revealed to protect them once more from the impact of the elements and returning the kivas to those long-silenced spirits of a vanished world.