INDIAN MOUNDS WILDERNESS, Texas -- Crews searching for shuttle debris have received government permission to use four-wheel-drive vehicles in a 12,000-acre federally protected wilderness area.
The U.S. Forest Service gave authorization Thursday to searchers in the Indian Mounds Wilderness, where motorized equipment has been banned since 1984.
"With an event of this magnitude, we have to look at the laws and make exceptions to make the right choice in a difficult situation," said Forest Service spokeswoman Gay Ippolito.
As of Friday, officials said, searchers had not driven any vehicles but had covered only a small part of the wilderness.
The last time motorized equipment was allowed in Indian Mounds was three years ago. Bulldozers were brought in when forest fires threatened the area but were never used, officials said.
Environmental groups were largely understanding about the shuttle recovery effort but expressed concern about the search's effect on East Texas forests overall. Indian Mounds is not far from the Louisiana line.
"This has been a pretty heavy footprint on the forest," said Richard Donovan of the nonprofit Texas Committee on Natural Resources.
Since Feb. 1, when Columbia broke apart, killing all seven astronauts aboard, thousands of volunteers, National Guardsmen and others have been walking through forests and tilling the muddy soil with four-wheelers and other motorized equipment.
Also Friday, searchers on foot and in all-terrain vehicles started combing five acres of federal Bureau of Land Management property in southeastern Nevada, about 30 miles from the Utah state line.
NASA officials said Thursday that air traffic control radar had tracked possible shuttle debris falling in eastern Nevada.
So far, no shuttle debris has been found farther west than the Fort Worth area.