Little did Domingo "Buzzy" Ybargoitia know that by drilling a well to bring water to his sheep, he would change the way we view the history of humans in the New World.

"My girls need to drink, that's all I was thinking about. It gets mighty dry around here come late summer anymore. I don't know what's going on, but I do know my granpoppa never had any trouble keeping his flock watered, and my pop didn't either. But I've had to truck it in from Marsing when it gets really hot."

Ybargoitia manages his family's sheep operation in Idaho's lonely Owyhee Mountains, an hour's drive over rough roads from the tiny Oregon village of Jordan Valley. Two years ago this coming April, he brought a drilling contractor from Nampa to install a dependable well. It was tough drilling until they got through the dense lime deposits, or caliche, that underlies so much of this remote southwest corner of Idaho.

"A couple of times, I was afraid those boys were going to give up," says Ybargoitia. "They'd pull their bit out of the shaft and just shake their heads when they saw how chunked up it was getting."

On the second morning of drilling, they unearthed an astonishing surprise. The hole was below the caliche, down to about 26 feet, when Ted Burquart of the drill crew pulled what looked to be a child's doll from the mud and sand accumulating next to the hole.

"At first, I just thought it was just one of those Troll dolls you see hanging from rearview mirrors," explained Burquart. "I wiped the crud off and took a better look at it. It was whittled out of rock, I could tell that much. And what I thought was crazy Troll hair all flattened out was really a funny little cap. Like a beret, maybe."

Ybargoitia knew immediately what it was. As a youth, he had spent too many years with the Oinkari folk dancers of Boise to not recognize a traditional Basque txapela, even if it was small enough to top a five-inch figure. He stopped the drilling and sifted through the pilings with his fingers, wondering what else might have been brought up. Within minutes, he had found several blades, chipped to a razor's edge on both sides, ranging from 9 to 20 centimeters long. Each one had a notch into which a spear haft could be set. He also found a small, partially eaten and mummified sheep thigh, impaled on a nearly petrified willow skewer.

"Back then, I didn't know a Clovis point from a Buck knife, but I sure as heck know a lamb kebab when I see one."

He was also relatively certain that all of these items -- particularly the primitive figurine -- were highly unusual coming from so far below the surface. Ybargoitia sent the drill crew home, gathered up everything he'd found into his lunch box, and called the Treasure Valley Community College in Ontario, Oregon. He was referred to the Cultural Anthropology Department.

"When Buzzy showed me those things, I about fell out of my chair," said Dr. Benton Schrall, the department head. "North American artifacts aren't exactly my field. Still, I recognized immediately that he had stumbled onto something very significant."

That afternoon, Dr. Schrall e-mailed a colleague at Washington State University in Pullman, who put him in touch with Dr. Lawrence Riggs, the chairman of WSU's Archaeology Department. Said Dr. Schrall, "When I described to Larry what I had, right there on my desk, the first thing out of his mouth was, 'Whatever you do, don't tell any Indians about it!' I guess he got burned pretty bad on that Kennewick Man deal."

With two of his brightest grad students in tow, Dr. Riggs drove to Ontario the next day. As soon as he saw the artifacts, he knew exactly what he would be doing for the next several summers. "Clovis points in Idaho? And from 7 meters down! That alone is an archaeologist's dream, without even considering the totem figure."

Fearful of letting that figurine out of his sight, Dr. Riggs shaved a thin specimen from the bottom of one tiny foot and sent it to Le Duchamp Laboratoire in Lyons, France, a world leader in intra-spectral comparative analysis. He then spent the next six weeks organizing what would become the largest -- and most covert -- archaeological dig in Idaho's history. Even Ybargoitia was sworn to secrecy.

"Larry Riggs had me sign a paper that said as long as I didn't tell anyone else about what I'd found, his university would foot the bill for another well. He came down on spring break, along with a nine-seater van full of students, and they set up a cyclone fence around that spot and put a tent over the hole. It about killed me that I couldn't tell anybody. It was like getting to be in a movie or something, only I couldn't even let my friends know I was in it."

The excavation proper began after the semester ended on May 21, 2005, and by Labor Day of that year, Dr. Riggs had confirmed what his instincts had been telling him since he first saw the figurine. Le Duchamp lab sent him their analysis of the sample in early July. They had tested the specimen three times, and for further confirmation, they had sent a portion to another independent laboratory in Quebec to verify their findings. There could be no mistake: The sample was from a unique soapstone found only in a region of northern Spain, on the southern slopes of the Pyrenees Mountains.

It took 10 weeks of excruciatingly detailed soil removal for the team to get down as far as the drill bit had reached, but at a depth of just under 8 meters -- the investigators came across a strata of soot and charcoal, indicating the remains of an ancient campfire. Within a 5-meter radius of that fire pit, they uncovered a dozen more spear tips -- sophisticated Clovis points, all of them -- the gnawed bones of several seemingly domestic sheep, a shredded remnant of what appeared to be a leather drinking sack (a bota), and a human skull.

By summer's end, Dr. Riggs had circumstantial evidence that early humans had migrated to this hemisphere from the Iberian Peninsula. But most astounding was the level at which this body of evidence had been found. The geological strata in which the items lay dated from a very narrow (and little understood) time frame known as the Proto-Paleolithic, indicating that human beings had put their footprint on the New World 40,000 years before anyone had previously believed possible.

Even more momentous were the "associative implicatory collateral traces," as they are called in the field of paleoanthropology, which implied that wherever these people came from, they brought their sheep with them.