Volunteers looking for a large piece of space shuttle Columbia's landing gear found several small scraps of aluminum in a remote part of Nevada on Saturday, but it was not immediately clear whether they belonged to the doomed spacecraft.

"They've found several pieces of material they suspect may be from the shuttle," said Col. Matt Wallace, commander of the Nevada Wing Civil Air Patrol. He said the pieces were several inches long each and looked like aluminum foil.

Ksheriff's office, said the debris had been digitally photographed and sent to NASA experts to determine its origin.

"We are hopeful," he said. "I can say it looks promising but I can't say for sure."

Eileen Hawley, a NASA spokeswoman in Houston, confirmed searchers recovered five pieces that need to be examined. "We are really not sure what this might be," she said. "We need to take a closer look. It's not obvious it has anything to do with Columbia."

If the pieces are from Columbia, they would be by far the westernmost bits of debris recovered from the shuttle, which broke apart Feb. 1, killing all seven astronauts on board.

People have combed vast areas in southern and western portions of the United States, but an area near Lubbock, Texas -- some 750 miles southeast of the Nevada search site -- is the farthest west confirmed debris has been found.

The Nevada search of about 30 square miles near Panaca, about 170 miles north of Las Vegas, began Friday and was expected to conclude Monday.

A NASA official told searchers that the hilly desert and knee-high sagebrush near the Nevada-Utah state line may contain a six-foot chunk of landing gear, said Bob Williams, a Lincoln County sheriff's volunteer and a spokesman for the Nevada search effort.

Finding the landing gear could give NASA investigators important clues about why the shuttle broke apart. The board investigating the accident has determined Columbia almost certainly suffered a breach along its wing and possibly its wheel compartment that allowed searing air to seep inside during its descent at nearly 12,500 miles per hour.

About 80 miles from Panaca in Utah's Washington County, sheriff's officials also began searching Friday at NASA's request. Sheriff Kirk Smith said the ongoing search had not turned up any confirmed shuttle pieces.