With 750,000 acres, hundreds of miles of trails and an unknown number of bears, Yosemite National Park has long been one of the nation’s most popular getaways, a stunning physical wonder whose international reputation and proximity to major California cities helped it draw four million visitors last year.
But it is a different number — 18 — that has been alarming both rangers and those seeking rest and relaxation recently.
Since the beginning of the year, 18 people have died in Yosemite, an unfortunate increase from recent years that has included a few terrifying deaths this summer, including three members of a church group who were swept over a waterfall and a pair of deaths from falling at Half Dome, the park’s signature peak.
The drumbeat of ominous news continued this Labor Day weekend, as park officials said they found the body of a 69-year-old hiker who had been missing.
And while Yosemite officials say there is no real reason for the surge in deaths — the most in more than a decade, experts say — they agree that the fatalities have been a tragic reminder of the perils of the great outdoors, particularly for those unaccustomed to it.
“We do get a lot of visitors who may not be familiar with nature,” said Kari J. Cobb, a park spokeswoman. “But it is nature. And it can be dangerous.”
One of the deaths came two weeks ago when a 23-year-old man, Ryan Leeder, fell off the front face of Half Dome, which rises nearly 5,000 feet from the valley floor, screaming as he went, something a witness likened to “the sound of a commercial jet near landing.”
Mr. Leeder’s fall is still under investigation, according to park officials, but foul play is not suspected. The death came on the heels of another one at Half Dome in which Hayley LaFlamme, 26, slipped in wet conditions. She fell 600 feet and was pronounced dead at the scene.
Such gruesome, headline-grabbing deaths have not been limited to Yosemite, of course. In late August, the body of a 59-year-old man was discovered in Yellowstone National Park, having been mauled and killed by a grizzly bear.
For all that, national parks officials say that the parks are not more or less dangerous than years past, and that many of the deaths are from more commonplace causes, like car accidents, heart attacks and suicides. Jeffrey Olson, a spokesman for the Park Service, said there had actually been fewer deaths at national parks so far this year — 113 through last week — than in the same period last year. And that is out of some 280 million annual visitors to the national parks.
“It’s a really, really small percentage of people who don’t make it home,” Mr. Olson said, adding that he thought the public was doing a good job of being safe. “We wish they did a little bit better job, of course. But you can trip on the curb at a park in Manhattan.” (True, though falling off a cliff is certainly less likely.)
Michael P. Ghiglieri, the co-author of “Off the Wall: Death at Yosemite,” with Charles R. Farabee Jr., said Yosemite was probably the deadliest park in the country, with about 900 traumatic deaths — those not attributable to a previous medical condition — since its establishment in 1890.
It is a record that Mr. Ghiglieri attributes in part to the park’s unique geography, with fast-moving water, glacier-carved canyons and towering waterfalls.
“These are humongous, gigantic, scare-your-pants-off kinds of waterfalls,” he said.
And often it is the actions of those who go to gawk at such marvels that are to blame, including, Mr. Ghiglieri said, the eternal quest for the perfect snapshot.
“In Yosemite, there is an attraction of having your picture taken right there in those waterfalls, especially now with Facebook and Twitter,” he said. “But even with old cameras the attraction was the same.”
Then, too, there are those who simply insist on pushing the limits — or pushing past clearly marked signs. It was just such a decision that turned fatal on July 19, when three 20-something visitors from an Assyrian church in nearby Ceres, Calif., fell into the Merced River, just above Vernal Fall, a 317-foot drop-off onto boulders below. The river was roaring, a result of the runoff from ample snows in the Sierra Nevada this winter, something that has made many of Yosemite’s waterways extra treacherous.
Witnesses to the deaths said that at least one of the victims had jumped the fence, slipped and fallen in, and that the other two died trying a rescue.
Jake Bibee, who saw the accident, told The Fresno Bee that the group was “taking pictures and being stupid” before tragedy struck.
“We had to watch the fear on their faces as they knew they were plunging to their death,” Mr. Bibee said. “It was awful.”
'Our Mount Everest'
There is also the danger of bravado. Half Dome, in particular, which is reachable only by a hike up an unrelentingly steep trail, is referred to by some aficionados as “our Mount Everest.”
And while that may be hyperbole, many who reach the final push toward the top of Half Dome — a 400-foot segment of cable at a 45-degree angle, often crowded with people — can make questionable decisions, like rushing or pushing ahead in bad weather.
“They call it ‘summit fever,’ ” said David Buchanan, 50, a regular visitor to Yosemite who has climbed Half Dome. “They’ve gone so far, not to make it to the top isn’t an option.”
This year, park officials have tried to limit the number of people who try to climb Half Dome by requiring permits. But the permit does not take applicants’ physical condition into account, Ms. Cobb said.
None of the bad news has seemed to hurt the park’s popularity. Yosemite had its busiest July ever this summer, with about 730,000 visitors. On Friday, a steady stream of cars plowed toward the park, while inside the gates, hundreds made the mile-and-a-half trek to the top of Vernal Fall.
The river’s flow was less violent than in July, but still rapid. Nevertheless, several visitors climbed onto rocks and fallen limbs just beyond the edge of a small fence to pose for photos or dip their feet in the icy water despite a sign saying swimming and wading was prohibited.
Such rule-bending leads to eye-rolling by Yosemite visitors like Randy Crawford, 45, who was sitting with his wife and three children near a shallow section of the river known as the Silver Apron, about 500 feet from the top of the falls. Mr. Crawford said he was strict with his children: no running, no jumping, no touching the water.
“They don’t go near it, and they don’t go near the wet rock,” he said. “This is not Disneyland.”
Jesse McKinley reported from Yosemite National Park, and Ian Lovett from Los Angeles.
This story, "At Yosemite, 18 Reminders of Dangers of the Outdoors," originally appeared in The New York Times.