A Texas scientist and an army of volunteers may be about to rewrite history, or more correctly, pre-history.

Most of us were taught that people have lived in North America for only about 13,000 years. Now an excavation in Williamson County may help challenge that theory.

"This is a scapula of a medium-sized animal, we haven't figured out yet what animal it is...but it's probably a campsite where they butchered lots of different kinds of animals for food," said Michael Collins of The University of Texas.

The Clovis People were hunter-gatherers who populated much of North and Central America. Scientists believed they crossed a now-submerged land bridge across the Bering Strait from Siberia to Alaska about 13,000 years ago. They were nomadic, following the wooly mammoth and bison herds, never staying in one place for long.

That's what most scientists believed. But in northwestern Williamson County, at what is probably the most important Clovis site yet discovered, Collins is finding things that shouldn't be here. "We find woodworking tools. We find delicate engraving tools. We find tools that were used to cut grass," Collins said.

He said there are sites in South America much older than the Clovis people are believed to be. Some scientists said people may have been in America for as long as 30,000 to 40,000 years, not just 10,000 to 12,000. "One reason I'm here is that for several years I have seriously doubted the theory that Clovis were the first people in North America," Collins said.

Without major government funding, Collins, a research assistant at the Texas Archaeological Research Laboratory of the University ofTexas, has assembled a small army of volunteers and graduate students. "And this is a late-stage biface, they're calling it, which means it's almost complete...not quite finished," Collins said. They are about halfway through a 3-year dig at what is called the Gault Site.

This 20-acre site is already one of the three most productive in the Americas. Collins believes it will be the most important of all of them in what science learns about the first people in America. "I've gotten into discussions with people in the grocery store that tell me flat out 'You can't find the first people. You willnever find the first people," Collins said. "No, but we can probably keep looking and get close, and that's the intriguing part."

But they are getting closer with this dig in Williamson County. The Gault site is on private property and was first discovered in the mid-1980s. The excavation began in 1999 and will end in May of next year.