TOWN OF ONALASKA — In a chilly Wednesday morning drizzle, her jeans soaked to the knees, Wendy Holtz-Leith sunk an aluminum tube into a patch of soggy earth. She pulled out a 30-centimeter plug of soil that could contain remnants of an earlier civilization.

A research archaeologist with the Mississippi Valley Archaeology Center, Holtz-Leith is surveying the future site of a federal wildlife center in hopes of learning a little more about the people who lived there 700 years ago.

The U.S. Fish and Wildlife Service contracted with the MVAC to study the site after a walking survey last summer turned up stone flakes.

The agency plans to start construction next year on a visitors center and headquarters on about a third of the 75.4 acres it acquired in 2008 from Mathy Construction.

Jim Nissen, La Crosse district manager of the Upper Mississippi River National Wildlife and Fish Refuge, said the site is among only a few locations that met the agency’s criteria: near the river and wildlife refuge — though out of the flood plain — with enough land for future expansion and a natural prairie with interpretive trails.

The Oneota culture developed in the 12th century in the upper Mississippi River Valley. They settled around what is now La Crosse about 1300 A.D. and stayed until just before the arrival of French fur traders 350 years later.

Unlike earlier hunter-gatherer cultures, the Oneota lived in villages of up to several hundred people, with extended families sharing wood long houses. They farmed corn, squash, beans and tobacco in raised fields.

Archaeologists know one village was on Brice Prairie near the river. They hope the Mathy tract excavation will tell them the extent of that settlement.

A bulldozer Tuesday cut 14 trenches in the alfalfa field that revealed 10 features — dark circular stains under the foot or so of soil disturbed by 150 years of modern agriculture.

Such circles often mark the grass and wood-lined food storage pits that later became garbage bins.

Garbage reveals what people ate — for the Oneota, lots of corn, beans and squash with occasional fish and venison — and used for tools, how they made those tools or whether they traded for them.

“That’s where we get most of our information,” Holtz-Leith said.

She measured the feature’s diameter and depth, then scraped a bit of soil onto a trowel and held it against her Mansell Soil Chart. Research assistant Miranda Alexander recorded the measurements and color — 10YR31 — on a soggy sheet of graph paper. Alexander, a UW-L graduate now at the University of Oklahoma, is working on a master’s thesis on Oneota architecture in the La Crosse area.

The archaeologists will return Monday, weather permitting, to excavate the features, digging in what they hope is very old garbage.