A man accused of looting thousands of artifacts, including human bone fragments, from an Illinois national wildlife refuge has been sentenced to a month in jail and five years of probation as caretakers work out what to do with the prehistoric trove.

A federal judge this week also ordered 50-year-old Leslie Jones of Creal Springs, Ill., to perform 500 hours of community service after his 30-day jail term and pay the Cypress Creek National Wildlife Refuge in southern Illinois more than $150,000 in restitution.

Jones pleaded guilty last October to excavation, removal or damage of archaeological resources without a permit -- a count that was punishable by up to two years in prison and a $20,000 fine.

At that time, Jones admitted he had sold some of the artifacts he unearthed at the refuge from 2004 through February 2007 to collectors and dealers.

The U.S. Fish and Wildlife Service says more than 13,000 artifacts -- including pottery, clay figures, stone weapons and tools, and more than 200 pieces of human skeletal remains dating from roughly 6000 B.C. to 400 A.D. -- were seized by investigators from Jones' home in early 2007.

Court records do not detail how many artifacts Jones may have peddled or exactly how much he profited; an investigator, the service's Geoff Donaldson, said Wednesday that prices for such historical pieces vary wildly according to the type of artifact, its condition and time period.

"We can't put a price tag on the damage he's caused," Donaldson said. "It's unfortunate because we've lost a resource. But sentencing aside, our biggest win out of this was that he was hit fairly significantly by the justice system, and hopefully he'll think twice before coming out (again) with a shovel and start digging for artifacts."

Jones had done his homework before looting the refuge, later telling investigators his research enabled him to identify pieces of artifacts and their time periods, Donaldson said.

"We considered him to be educated, particularly in the area of archaeology," Donaldson said. "He knew what he was doing."

Jones' federal public defender declined to publicly discuss the case Wednesday.

Donaldson said investigators were trying to figure out the next stop for the artifacts, which have been sorted and bagged according to their type and time period. More than 200 of the pieces are fragmented human bones.

"We're just going to have to find a home for all this stuff," most likely at educational venues and museums, he said.