Some 7,000 years ago, nomadic hunters and gatherers began passing through the area we now call Santa Fe.

Beginning about 1,500 years ago, small groups started staying long enough to plant, cultivate and harvest corn.

And 700 years ago, during a period of hard times, they began to build fortified villages, including one on the north side of the Santa Fe River and another to the south along the Arroyo Hondo.

These are some of the things archaeologists have learned about the history of the area from excavations in recent decades in downtown Santa Fe and other parts of the region.

On Saturday from 1 to 5:30 p.m., these findings will be the subject of a symposium titled "Beneath the City Different: The Archaeology of Santa Fe," sponsored by the School for Advanced Research and Friends of Archaeology with support by the Old Santa Fe Association. The event, at the New Mexico History Museum auditorium, has been sold out since early October.

Stephen Post, deputy director of the Museum of New Mexico's Office of Archaeological Studies, will speak on the early hunter-gatherers and the "dawn of agriculture" in the Santa Fe area.

In a recent interview, Post said archaeologists have known for years that corn was cultivated in Santa Fe by 1300 A.D., but recent digs found evidence of agriculture up to 900 years earlier.

While excavating the Santa Fe Community Convention Center site, Post said, the archaeomagnetic specialist told him that two charred corncob fragments had been dated to between 400 and 600 A.D.

"I said, 'No way. It just can't be,' " Post said. "So he found a couple more, and darned if the dates didn't come back the same. ... Two times, I might say it was aberrant, but with four, I started to believe him. What we were looking at was this incipient agricultural population that had settled just long enough to apparently grow corn and harvest it in that heavily flooded area between the Santa Fe River and the Arroyo Mascaras."

Douglas Schwartz, senior scholar at the School for Advanced Research, said the pueblo village in what is now downtown Santa Fe was just one of the larger settlements that sprang up around 1300 A.D. Schwartz will speak on his excavations of a similar prehistoric village along the Arroyo Hondo, two miles south of Santa Fe, in the 1970s.

"Prior to 1300 ... was a great time for early farmers and hunters and gatherers," he said. "The temperature was good. The precipitation was good. And there were just hundreds of small settlements throughout the northern Southwest.

In the Rio Grande Valley, small settlements began to band together into larger settlements around 1300 with a period of global cooling dubbed the Little Ice Age. "As a result of that, farming became very difficult — limited resources, famine, and with famine comes conflict," Schwartz said. "It appears as if they came together from small open sites into a few large sites that are defensive. ...

"They came together to defend themselves from neighbors. These weren't barbaric people that were coming out of the mountains or the north. They're fighting one another. Actually, the fighting may have been less important than protection from fighting. There's an old saying that conflict is inevitable, but combat is not. It's like walled cities in Europe. If you could protect yourself, then you don't have to fight all the time. ... (Arroyo Hondo) is not a settlement, it's a citadel."

Prehistoric settlements won't be the only subject at Saturday's seminar. Cordelia Thomas Snow, historic sites archaeologist and historian for the state Historic Preservation Office, will speak about what recent excavations downtown have revealed about the earliest Spanish settlements.

"We have expanded our knowledge of what the casas reales looked like in the 1700s," she said. "We still only have little windows opened up, but we have a much better idea of what things looked like and what people were using and the whole material culture."

Snow said, for example, that we now know that some of those early colonial buildings were two stories and that although the Spanish built along the Santa Fe River, much of that part of the city was devastated by a flood in 1767.

"The flood was probably on a par with a 100-year flood — maybe even a 500-year flood using today's terminology," she said. "The flood was so great that huge boulders closed the main channel of the river, forcing water down what is now Water Street and flooding out the entire area, endangering the Plaza."

Jason Shapiro, a lawyer turned archaeologist who is chairman of the city Archaeology Review Committee, will speak on Santa Fe's early archaeologists — from Adolph Bandelier in the late 19th century to Edgar Hewitt in the early 20th. "They were creating archaeology," he said. "There wasn't a field of science, a discipline of archaeology. It was developing. ...

"They don't have much to rely on. They're not making it up as they go along, but they're thinking, they're doing their digging, they're studying and they are creating archaeology. My point is, archaeology is cumulative. We build on everybody else's knowledge."

Shapiro said artifacts collected downtown have included ivory from Asia or Africa, porcelain from China and other items from around the world, leading him to believe Santa Fe may have been more cosmopolitan than previously thought.

"Here's this little outpost, this colonial outpost at the very edge of the Spanish empire, and all of this exotic, expensive and fancy stuff is still finding its way here," he said. "So maybe it's not such a little outpost at the end of forever."

Other archaeologists speaking Saturday include Timothy Maxwell, director emeritus of the Office of Archaeological Studies, who will give welcoming remarks; Cherie Scheick of Southwest Archaeological Consultants who will speak on changes in Santa Fe in the 12th and 13th centuries; Ron Winters, an independent archaeologist, on the Santa Fe Trail, and Jessica Badner of the Office of Archaeological Studies, on discoveries around the Santa Fe Railyard.

Contact Tom Sharpe at 986-3080 or tsharpe@sfnewmexican.com.