It used to be enough to climb the mountains, blaze the trails and ride the rivers - but not anymore.
Chris Hartfield and other adventurers are addicted to the drug of the 1990s: adrenaline. 48 Hours Correspondent Russ Mitchell reports.
In a secret location in California, Chris Hartfield goes out for his morning jolt.
"I wake up a little bit differently than most people in the morning," he says. "They get up and have a cup of coffee, and I go out and jump off a cliff to kind of wake myself up. The adrenaline keeps me going."
The location is secret because what Hartfield is doing is usually illegal. His sport is called "BASE jumping," taking a dive off of anything high with just a parachute.
(BASE is an acronym for building, antennae, span, earth, and stands for the fixed-objects from which BASE jumps start from, according to the Skydive! Web archive.)
"Life is pretty short, so I try to take advantage of it while I'm here. You can't take all your toys with you, and, you know, you might as well live it while you're here," Hartfield continues.
Paul Ruff had also liked to be daredevil. His extreme skiing was featured in commercials and movies. But even for the experts, one mistake is all it takes.
Six years ago before Ruff jumped off of a 160-foot cliff and hit the rocks at the bottom, he had planned the stunt for a Mountain Dew commercial.
Despite the ad's diminutive caption that gives a warning, many Americans try deadly imitations.
Many of these imitations are done in Yosemite National Park. Host to as many as 30,000 visitors on summer holidays, Yosemite has the busiest search and rescue center of all the national parks.
Despite its danger, BASE jumping is growing more and more popular.
One holiday weekend morning, the first call came in at 6:35 a.m. A lone mountain climber Derek Hersey is overdue.
Hersey is a mountaineer who specializes in something called "free soloing," climbing mountains without ropes. For other climbers, the rope is literally a lifeline. Without it, a simple mistake can be fatal.
Having earned the nickname "Dr. Death" from his friends in Colorado, Hersey is famous in the climbing community for his amazing feats and for pushing the limits of the sport to daring new heights.
Ranger Scott Bowen is assigned to lead the search for Hersey.
"We're going to take another look. He should have been down by last night," Bowen ays. Such a search, he says, can easily cost more than $10,000.
It is exteremely tough to spot someone in this vast wilderness. Yosemite Park spans 747,956 acres - or 1,169 square miles of wilderness.
Besides the hunt for Hersey, there is also word of a plane crash in the park. Two helicopters and more than a dozen rangers are searching, stretching park resources thin.
Last year there were more than 6,000 search and rescue missions at Americas national parks - a jump of nearly 50 percent from the year before. The cost: more than $3.5 million.
Some of the missing were daredevils like Hersey, but many were ordinary tourists who sought their thrills a little too close to the edge.
Should visitors be charged for the cost of rescue?
"You talk to the taxpayers who say that, 'Well, you spend a half million dollars of my money rescuing people who are doing dumb things or dangerous things,'" says Bob Andrew, chief ranger at Yosemite National Park. "'That's not right. They should have to pay for it themselves."
Right now taxpayers are picking up most of the tab. The U.S. Coast Guard spends some $380 million each year on search and rescue missions.
In July it hoisted 14 hikers from a mountain in Alaska after they became lost and fatigued. And last Christmas it rescued British tycoon Richard Branson off the coast of Hawaii, when he decided to abort an around-the-world balloon flight. Branson claimed he would have paid the more than $100,000 spent to save him but he was never billed.
"It's not Disney World," says Cameron Jacobi, a Yosemite ranger. "Those are real rocks. It's real water. That's really a long way off the ground."
Jacobi remembers rescuing a man who fell a thousand feet down the face of a mountain. During the rescue, Jacobi fell and tore up his foot. He was out of work for seven months.
"I was irritated with the guy," he says.
Chris Hartfield was rescued by Yosemite rangers.
The man he rescued was Hartfield, the BASE jumper. Though the jump almost killed him and the rescue cost thousands, he feels no guilt and is ready to jump again.
"I do pay my taxes like everybody else. So I'm glad they're there and they were able to help me out," says Hartfield.
About two and a half hours into the search for missing climber Hersey, Bowen's team receives a tip. The search and rescue team indicates the situation may be Code 1144: the code for a fatality.
By noon friends of Hersey gathered, and the news is not good. After several hours, a team finally reaches the spot and confirms Hersey's death.
It takes quite a few more hours tlower Hersey's broken body down the cliff: It is a grisly task. Rescuers hope this will serve as a reminder to other adrenaline junkies of the potential consequences of their behavior.
Elsewhere in the park, a helicopter spots the plane crash with four fatalities there, making it one of the deadliest days in Yosemite history.
But the rescuers have missed the point. In this game, death is the opponent, and the Chris Hartfields of the world will tell you all the fuss over risks and rescue will never stop them in their search for an even higher-risk high and the chance to walk away one more time.