"We are tasked solely to find out where it is," said Darrel McDonald, coordinator of geology at the university. "Once we're finished they can move the sensitive pieces."

In Nacogdoches County, the apparent epicenter of debris, the recovery mission has been reactive. It's all they can do to keep up with the reports that come in. But once the calls slow down, Sheriff Kerss said, officials will turn their attention to less populated areas of a county that is 65 percent forest land.

In Sabine County yesterday, hundreds of searchers dressed in high boots and thick work clothes methodically moved through the forest, working in strict grids in their quest for clues. This is where the majority of the human remains have been discovered, including a torso, thigh bone, skull and a charred leg - and the volunteers and law enforcement officials know that. NASA retracted an earlier statement by one of its senior officials that remains from all seven of the dead Columbia crew members had been found. This part of the search is particularly unnerving for these crews.

"It's traumatic," said Billy Ted Smith, emergency management coordinator for Sabine and two neighboring counties.

The briars here are so thick in spots that the rabbits have trouble navigating them. Some objects could have burrowed into the ground upon impact. One searcher - who worked miles down a winding dirt road outside of Hemphill - said he hadn't found much aside from "trash and beer cans."

Out here they can't sit around and wait for the phones to ring, because they probably won't. Some of these pine forests rarely get human visitors.

"We can't wait that long," Smith said, "we'd be waiting for years and years and years."

On the Stephen F. Austin campus yesterday, officers were standing guard over the 20 or so objects found there over the weekend. Once those are removed, the school will turn its attention to its own search for what might be lurking in its woods.

"That will be going on for a very long time," said Marc Cossich, the school's chief of police. "Some of these areas are so remote, I'm anticipating hunters finding them a year from now."

The Associated Press contributed to this article.