With their unique mix of grand vistas, scenic wonders and rugged terrain, America’s national parks draw hundreds of millions of visitors each year but occasionally serve as a reminder that Mother Nature is unforgiving.

As the unofficial end of summer looms this Labor Day weekend, 2014 has already seen a number of high-profile of park fatalities. Among them:

In May, six climbers were killed in a fall at Mount Rainier National Park, the worst disaster there in more than 30 years.

On June 9, a man in Yellowstone went off-trail to get a better view of Grand Prismatic Spring and was killed when a lodgepole pine fell and struck him in the head.

On July 13, a woman at Glacier National Park slipped and fell into McDonald Creek while trying to take a picture and was swept over a waterfall. She died the next day.

Also in July, two people were killed by lightning on two consecutive days at Rocky Mountain National Park, the first lightning deaths in the park in 14 years.

On Aug. 16, veteran climber Brad Parker fell to his death while climbing in Yosemite, just hours after proposing to his girlfriend.

On Aug. 17, an 8-year-old girl lost her footing and plunged 550 feet into the Grand Canyon of the Yellowstone.

“As the economy has gotten more robust, we’re seeing an increase in visitation,” said Ken Phillips, branch chief of search and rescue for the National Park Service. “Any time visitation goes up, we see emergency situations go up.”

National parks received 273.6 million total visits in 2013, down 3 percent over the previous year largely due to the government shutdown, which forced national parks to close for the first 16 days of October. But many parks have seen a record number of visitors in recent years, including Yellowstone National Park, which hit an all-time high of 3.6 million visitors in 2010, and Glacier National Park, which saw a monthly record of nearly 700,000 visitors in July.

There were 148 fatalities in national parks last year — up from 143 the year before, according to the National Park Service. However, visiting a national park is still statistically much safer than, say, driving in your car to get there.

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In 2013, national parks also saw 2,348 incidents that led to search and rescue efforts, according to park statistics. Of those, says Phillips, 557 would have likely resulted in fatalities without intervention.

The most common factor for accidents? It’s not caving, climbing or even cliff diving, but day hiking, which accounted for 37 percent of all search and rescue calls. Part of that, of course, is because there are far more day hikers than cliff divers, but it also speaks to issues of experience and preparedness. More than one-half (53 percent) of search and rescue calls involved contributing factors of fatigue/physical condition, insufficient preparation (such as lack of proper clothing or equipment) or errors in judgment.

The Grand Canyon is a prime example of such issues due its popularity, blistering temperatures and a unique topography that essentially turns traditional hikes upside down.

Rescuers at Grand Canyon National Park use a wheeled litter to evacuate an injured hiker from the Bright Angel Trail. NPS photo

“Hiking downhill, you’re lured by the cooler temperatures on the rim and the beauty of the canyon, but then you have to turn around and hike back out and it’s only gotten hotter,” said Brandon Torres, branch chief of emergency services. “We see it fairly frequently that people just underestimate the journey.”

The park's website advises travelers to check the weather forecast in advance, avoid hiking alone and to stay on the trail.

Visitors to other parks at times seem to throw judgment out the window entirely. At Yellowstone, park officials deal with a steady stream of visitors who opt to get a little too up close and personal with the park’s elk, moose and bears.

“There are stories going back of people putting jam on their child’s cheek so that the bear would lick it off for the great photograph.”

“[Wildife] creates a wonderful visual spectacle, but it’s also a visitor-management challenge,” said spokesman Al Nash.

“There are stories going back of people putting jam on their child’s cheek so that the bear would lick it off for the great photograph.”

Visitors encounter an elk in Yellowstone National Park. NPS photo by Neal Herbert

In the past, park visitors were more likely to have a rural connection and experience with large animals, Nash said. Now, a number of visitors no longer have that experience to draw upon, so when they see an elk or grizzly bear or bull bison, "they mistakenly believe that that animal is safe and domesticated, which is certainly not the case.”

Yellowstone National Park's website advises visitors to stay at least 100 yards away from bears and wolves and at least 25 yards away from other large animals, such as bison, elk, deer, moose and coyotes.

Fortunately, most of the park's animals opt not to engage with smartphone-toting intruders, Nash said. But that hasn't stopped visitors from trying to get that perfect photo with the park's wildlife. These days, he said, “it’s more common to have them turn their backs to a wild animal so they can get a selfie with it.”