A Long Buildup and a Fast Collapse

The earliest settlers in the Tonto Basin were most likely migrants from the Hohokam core areas in what are now Phoenix and Tucson, where tens of thousands of people tended hundreds of miles of irrigation canals. But they soon evolved their own vibrant culture. They made beautiful pots, painted with elegant, curved designs suggestive of bird wings and sunbursts, that were traded or emulated across the Southwest. They built great food storehouses, reaping the bounty of a frost-free climate that offered rich wild plant resources plus three plantings a year. They buried their dead reverently, along with possessions treasured in life, usually close by their settlements. In one touching case of professional pride, archaeologists unearthed the simple burial of a man interred with his potter's tools and a lump of unworked clay. Often, the Salado buried their babies in the floors of their houses, as though the family sought to protect the spirit of someone too young to have mastered death alone.

Clearly, Salado society grew increasingly complex and stratified as they farmed 44 miles (70.8 km) of streambed. Many lines of evidence converge: the shift from largely ceremonial platform mounds to bustling food storehouses; the first signs of upper-class houses atop the mounds; the concentration of weapons and precious resources like turquoise at the later mounds; an increasing shift to reliance on irrigated crops; the emergence of specialists, like potters.

Then, however, their complex civilization collapsed in a matter of decades. Strangely, no major shifts in the stream coincided with the abandonment, which rules out flood or drought that destroyed the irrigation systems. The 1400s also brought no record-breaking droughts, according to tree-ring studies. Small droughts came and went, but that is not unusual in a watershed where the runoff varies each year from 2.6 million to 162,000 acre feet (enough water to cover one acre to a depth of one foot). The Salado weathered many such droughts during the centuries of their occupation of the valley.

Unfortunately, firm answers must wait on years of analysis as the scientists try to assemble clues to this absorbing missing persons case. “I still don't know why I was drafted in '68, and I'll never know why the Salado disappeared, but I can make good guesses about them both,” noted Jacobs. “I'm always trying to get into their position, but I don't even have an appreciation for what would have been a comfortable day's walk. Most Americans know when Easter is, but they don't know it's the first Sunday after the first full moon after the vernal equinox. Americans have no appreciation for what goes on out there at the horizon and where the stars go. I'm sure the people who lived out here 1,000 years ago knew all about that.”

At the moment, the evidence suggests the Salado were overtaken by a disaster of their own making, which offers a cautionary tale for modern societies. Perhaps they grew so numerous and so dependent on irrigated crops that a drought they once would have withstood did them in because they had denuded the wild resources of the basin. Perhaps they were affected by the collapse of the Hohokam civilization to the west, epidemics, or warfare with both one another and outside groups that caused their civilization to become more divided and class conscious.

Already, archaeologists have found one tantalizing suggestion that warfare played a tragic role in Salado society. The story emerged fitfully as the archaeologists shifted through centuries of dirt. First they found burned roof beams lying in disorder on the floor. Then they found an arrow point, embedded in what had been a doorway. Finally, trapped beneath the burned roof beams, they found three skeletons, lying facedown on what had been the floor of their home. Evidently, their settlement had been raided. The waist-high compound walls would have provided little protection from determined attackers. They had taken refuge in their home, only to have it set afire. They died there, testament to the persistence of human striving and malice.