Wild-animal attacks and mountain-climbing accidents command the biggest headlines, but search-and-rescue teams are called out most often to help lost or injured hikers in America's national parks.
The National Park Service reports spending $3.5 million last year on 3,108 search-and-rescue operations - 1,264 of them to assist hikers.
Even though the cost went up about $500,000 last year compared with 2002, the Park Service has no plans to change its policy of absorbing the expense itself. Only rarely does the agency go to court to seek reimbursement for a mission, and those cases involve severe negligence or fraud, Park Service official Dennis Burnett said.
A single, lengthy search-and-rescue mission involving helicopters and many federal personnel can cost hundreds of thousands of dollars, he said.
"Most folks from Middle America who that happens to are not in a position to pay that kind of a cost," Burnett said.
Hikers in need are a miniscule percentage of the 266 million annual visitors to the 385 units of the national park system.
Mary Margaret Sloan, president of the American Hiking Society, said her group provides safety information to members and urges them to check with each park about weather or trail conditions.
She warned the growing number of people who take cell phones into parks not to be confident that a call will get them out of a jam. Large areas of federal lands have spotty or no cell phone coverage.
"It's much better to take safety precautions beforehand so you don't get yourself into a predicament," Sloan said.
The largest number of emergencies - 34 percent - are reported in person, according to 2003 Park Service records, while 13 percent are reported by cell or satellite phone. Other reports of accidents come through locater beacons, CB radios, marine radios and regular phones.
One challenge for the national parks: Getting safety information to more visitors to prevent emergencies. Some visitors come ill prepared, according to accident reports this summer.