Another possibility is that population growth forced people down from the mountain slopes and onto the plains, where the Murgab then flowed lazily into a delta, creating an oasis of dense brush teeming with game, fish, and birds. That could explain why so many Oxus sites are built on virgin soil, as if carefully planned in advance. "The people came from the foothills of the Kopet-Dag with baggage, a knowledge of agriculture, irrigation systems, metal, ceramics, and jewelry making," says Iminjan Masimov, a retired Russian archaeologist who once excavated Oxus sites in Margiana.

Indeed, many Kopet-Dag sites appear to have been abandoned about 2000 B.C., just around the time Gonur and nearby sites took root. Hiebert's excavation at Anau, however, shows that it at least remained inhabited even as Gonur flourished.

While scholars debate the relationship between the Oxus culture and other early urban settlements, there is no dispute about the importance of the Kopet-Dag as a natural highway for nomads, traders, and armies between the Central Asian steppes and the Iranian highlands. The evidence is unmistakable when Hiebert shows me around the ruins of a medieval mosque on the summit of one of Anau's mounds. Damaged by time and earthquakes, the edifice is still famous for the two serpent-dragon mosaics—showing more the influence of China than of Mecca—that once guarded its facade. Around us are hundreds of mysterious little constructions, Stonehenge-like, each made of three small bricks. Hairpins and bits of cloth—probably linked to Central Asian shamanism—are scattered about the hilltop. Women come here to pray for children. One family, three generations of women, sits silently in a row by a tomb. Hiebert casually picks up glazed Iranian ware and a bit of Chinese blue pottery. "Here is your Silk Road," he says.


These tiny figures show not only the craftmanship of the Oxus people, but also the importance of animals in their culture.

Courtesy of Kenneth Garrett

The find dovetails with Sarianidi's work at Gonur, where he has found a Mesopotamian cuneiform seal not far from an Indus Valley stamp bearing symbols above an etched elephant. Both lay near small stone boxes similar to those manufactured in southeastern Iran. These items provide tantalizing hints of commercial traffic on a Silk Road predating by two millennia the trading route that eventually linked China to Europe in the early centuries A.D. Hiebert likens the Oxus civilization to Polynesia—a scattered but common culture held together by camels rather than canoes.

Sarianidi sees the settlers of the Oxus region as traders, not just in goods but also in faith. For him, Gonur is the capital of a people who came from the West with a religion that evolved into Zoroastrianism. In the long, still desert evenings at his camp, he speaks of migrants fleeing from drought-plagued Mesopotamia to this virgin land, bringing a conviction that fire is holy, as well as techniques for brewing a hallucinogenic drink called soma. Eventually, some wandered farther east, part of the migration of Aryans on horseback who conquered India about 3,500 years ago. This theory of his finds little support, however. "Sarianidi has persuaded few if any archaeologists of his strongly held opinions," says Lamberg-Karlovsky.

Sarianidi may be the last archaeologist in the mold of the 19th-century adventurer, with a larger-than-life swagger, a sharp tongue, and a thick stubborn streak. Few researchers today can claim to have laid bare acres of ancient settlements virtually unknown a generation ago. The desert freed Sarianidi from the repression of the Soviet Union. In return, he uncovered the lost history of the desert.

On the excavation team's last night at Gonur for the season, we picnic in the desert, reclining on rugs and pillows like Turkomans, toasting with vodka like Russians, and enjoying roast lamb as Oxus shepherds no doubt did four millennia ago. "Here you understand who you are," Sarianidi says, lying like a pasha on his cushions. A stocky and robust man, he looks worn, almost frail, in the twilight. "I am one of those who cannot go on living without the desert. There is no place like this in the world. I want to be buried here."

Find out how current efforts are helping to transform the Aral Sea, whose water was once diverted into Turkmenistan and turned into a desert wasteland, back into a haven for life.

Scientists brave the harshest regions of Central Asia to learn about the migration of our human forebears.