SAN MARCOS, TEXAS — Six millennia ago, bison roamed the landscape along the Balcones Escarpment, where water flowing from San Marcos Springs formed a boundary between the level Blackland Prairie and the rocky terrain of the Texas Hill Country.
And where bison roamed, hunter-gatherers followed in pursuit of the large animals that provided life-sustaining meat and hides.
Now Texas State University students are digging into that past, painstakingly inching their way through 6,000 years of sediment deposits at the Texas Rivers Center in pursuit of old flint arrowheads and other items that the nomadic people discarded into their hearths.
"What we are finding are the things they threw away," said Britt Bousman, assistant professor of anthropology and director of the university's archaeology center. "But we can use those as clues to understand how they lived in the environment."
A dozen undergraduate and graduate students have spent the past three weeks excavating at the site just outside the historic hotel that now is part of the university's Aquarena Center. They're taking a summer course that's teaching them how to properly excavate and document the findings from an archaeological site.
It also is stirring their fascination with times long gone.
"They are neat to look at," said Deidra Black, sitting at a picnic table beneath a giant pecan tree with a small collection of flint arrowheads. "But if we know where they came from, they can tell you so much more."
This is the fifth year that Texas State students have worked at the site. They have reached a depth of about 51/2 feet, dating to a time when a hunter-gatherer group known as the Calf Creek Indians followed the bison herds down from what is now Oklahoma, Bousman said.
The period actually marked a respite from an extremely dry period that parched Central Texas for about 2,500 years in the early Holocene period, he said. But when rains came, vegetation drew the animals south into the area around the springs.
"When the bison came back 5,000 to 6,000 years ago, those people were following them in a big way," Bousman said.
The search for clues is slow and exacting. Inside the excavation pit, students divided the floor into a grid, then worked carefully with trowels and small shovels, removing soil an inch at a time from a section and loading it into plastic buckets.
Each bucket was labeled and carried to an area where the dirt was filtered through a screen, rinsing out any particles of bone or debris.
After the dig concludes this week, Black will analyze the artifacts and use the data to write her master's degree thesis.
After graduation next spring, she plans to work in archaeology, fulfilling a quest that began in childhood when her parents regularly took her on vacations through museums across the South.
"I told my mom then that I was going to live in Austin and be an archaeologist," she said.
This fascination with the past has continued into adulthood.
"I can just sit there and stare at the dirt and rocks for hours on end," Black said.