Crews preparing for the construction of an oil pipeline through northeast Nebraska have turned up more than dirt; they found prehistoric artifacts.

Jeff Rauh with the Keystone Pipeline project says a pre-construction crew found the artifacts southwest of Hartington.

He says an archeology company is preparing a report for the Nebraska Historical Society.

During a recent two-week period, archaeological experts found small bones, items that may be arrowheads and an area they believe was a campground.

Archaeologist Terry Steinacker of Nebraska's Fort Robinson State Park says a preliminary report dates the site from 1 A.D. to 900 A.D.

Rauh says the pipeline project is still on schedule, despite the find.