Archaeologists digging at a southern Illinois airport have uncovered Native American artifacts dating back to 1,000 years ago.

Crews with the Illinois State Archaeological Survey discovered five house plots from the Mississippian Era at the Southern Illinois Airport in Murphysboro. The dig also uncovered a stone ax that is thousands of years older than the plots. It would have been used to cut trees and wood.

The Southern Illinoisan reported on Friday that the archaeological excavation was required before the airport could be expanded.

Gary Shafer is the airport's manager. He says he knew the area had history, but added that the discoveries ended up being much "denser" than anticipated.

Archaeologists say they'll continue working at the area for a few more weeks to search for more artifacts.