In Southern California, where urban sprawl meets pristine wilderness, one can stand on a backwoods mountain trail and be so close to the city as to still hear the rumble of traffic and make out a downtown skyline.
Which is something, wilderness experts say, that can lead to a false sense of security.
Earlier this week, two teens hiking in a section of the rugged Cleveland National Forest that is only a couple miles from a shopping mall may have fallen victim to just that when they wandered off a trail and were lost for days.
Nicolas Cendoya and Kyndall Jack had planned a short Easter Sunday hike on a moderately easy trail in a section of the Cleveland National Forest that serves as the backyard for the suburban Orange County neighborhood where they live. When they wandered off the marked trail that afternoon and couldn't find their way back, however, it took authorities days to find them.
Badly dehydrated and nearly incoherent when rescuers located them, both were lucky to have survived. They are recovering in Southern California hospitals.
That's a scenario that should almost never happen, but it happens all the time in Southern California, said Mike Leum, who headed a team that hiked up a near vertical canyon wall on Thursday to rescue Jack from a small rock outcropping where the 18-year-old had taken refuge. Cendoya, 19, was found nearby the night before.
There were a record 560 similar rescue efforts carried out in Los Angeles County alone last year, said Leum, reserve chief of search and rescue for the Sheriff's Department.
"A lot of these places you can see downtown Los Angeles from," Leum said, noting that may give some hikers an extra feeling of security when they head out for what they believe will be just a short day hike.
But even being minutes from a city of 3.8 million, or in the case of Jack and Cendoya a short drive from a suburban shopping mall, means nothing if you can't get back down the mountain you've just climbed up.
"And you have to spend the night there in freezing temperatures and you're not prepared for it, then you're probably not going to survive," he said.
In Jack and Cendoya's case, the weather was mild every night they were trapped in the forest's Falls Canyon, but they ran out of water by the end of their first day.
Although they managed to place a 911 call seeking help, their cellphone battery died before authorities could pinpoint their location. And although the sprawling expanse of Southern California suburbia is clearly visible from the forest's ridgelines, in the canyon where they were trapped the brush was so thick they couldn't find a road that was just 500 feet away.
Although four national forests with more than 2,000 miles of hiking trails dot Southern California, experts remind that, while the area may be crisscrossed by freeways and filled with high-rise buildings, that's wilderness people are heading into and they need to be as prepared for it as they would be entering a backcountry area that's a hundred miles from a city.
There's no excuse, they say, for not bringing sufficient water, decent hiking shoes, proper clothes and other provisions.
"I'm not saying take a burro and have it loaded down with supplies," said Ron Silverman, senior director of the Sierra Club's Angeles chapter. "But what I am saying is think it through. If you're going for just an hour, you want a full bottle of water. And you don't want to take a sip and leave it in the car because you don't want to carry it with you. Bring the bottle."
But most importantly, say Silverman and others, don't go off the marked trail, no matter how good a hiker you think you are and not matter how close to civilization you may be. It was put there by other experienced hikers who marked it for a reason, to keep people from getting lost in areas they may get trapped in.
Such advice is often posted on forest websites and at ranger stations but Silverman said people often don't follow them, sometimes because they figure it's just a short time.
Other times there are other reasons involved.
"Some people, they just want to get adventurous," said Silverman. "It's that sense of adventure, that 'Oh, I can do that,' that gets people into trouble.
"If you want adventure," he adds, "ride a roller coaster. Be outside to enjoy the beauty of nature."