(CNN) — The urge to get a bit closer to Yosemite National Park's waterfalls or Yellowstone National Park's majestic bears is so tempting.
Yet so many of the US National Park Service sites are wild natural wonders, with dangers such as unpredictable weather, epic precipices and wild animals that may view you as a threat.
A visitor to Yosemite National Park fell to his death last week, a tragedy that park officials say may have been prevented if he had stayed on the marked trails.
Our national parks are not zoos, with animals caged to protect you from aggressive behavior, and it's not safe to ignore the rules, National Park Service officials say. It's important to read up on your national park destination and follow rules and guidelines posted in the parks.
Why do people get hurt?
A grizzly bear roams near Beaver Lake in Yellowstone National Park.
With 318 million people visiting National Park Service sites in 2018, there are bound to be injuries and deaths. (The park service's 419 sites include the 61 famous national parks, national seashores and lakeshores, historic parks and national monuments.)
The rise of the selfie seems to have emboldened more people to step off trails to take the epic picture of that perfect (but dangerous) geyser or that adorable mama bear with her cubs (who may attack if she thinks you are threatening her cubs).
At the same time, people who are not used to spending time in nature may think they're not in danger, despite rules and guidelines stating how far visitors should stay from mating elk at Yellowstone or how much water to bring to Death Valley National Park.
"The beauty of our national parks is that they are relatively wild in nature; basically wilderness classrooms which create obvious dangers that need to be respected," says Pete McBride, an experienced adventure filmmaker, photographer and writer who hiked the length of the Grand Canyon and nearly died during his first attempt.
"National park trails and warning signs are there for very good reasons: to protect not only the parks from degradation but also our own physical safety."
Kerry Gallivan, founder and CEO of Chimani, a national parks app, says that living in a relatively safe society with all sorts of crosswalks and other warnings may contribute to our ignorance.
"Our national parks are meant to be preserved in their natural state as much as possible, which minimizes the amount of safety precautions which can be installed," says Gallivan. This environment "is not something most people are used to, especially visitors who are used to living in urban/suburban environments."
Enjoy the view and respect the power of nature at Cook's Meadow and Yosemite Falls at Yosemite National Park.
David Calvert/Getty Images
Most National Park Service sites have plenty of safety information posted online to study in advance, and park rangers want to help you stay safe while enjoying the parks. Talk to a ranger, get your National Park Service passport stamped at a visitor center, and head out safely to explore these amazing national parks.
With a reminder that a picture of that off-trail waterfall or roaming grizzly bear isn't worth your life, here's our guide to staying safe while enjoying the amazing nature to be found at US national parks, known as "America's best idea."
Stay on the trails. Sometimes, it's that easy. The national parks spend a good chunk of their resources creating and maintaining trails for public use. Stepping off the trails, especially in parks with slippery slopes, crumbling cliffs and deep canyons, isn't safe.
Stay away from the animals. For Yosemite's black bears, it's at least 50 yards. At Yellowstone, the guidance is to stay at least 100 yards away from wolves, black bears and grizzly bears, and at least 25 yards from bison and elk. Not sure whether to run or climb a tree? Read up on park guidelines to find out. (Some bears are excellent tree climbers.)
Do you see that adorable mama bear with her cubs or that elk sow with her calf? Stay even farther away. Animal moms are even more dangerous if they view you as a threat to their young.
Stay alert when hiking in bear country. Making noise and hiking in groups helps to let bears know you're there. Carrying bear spray is also a good idea.
Pack up your food. Make sure you don't leave food around for animals to take at your camp site or on a hike. Park officials may have to remove or kill wildlife that become used to humans and their food, to protect human visitors to the parks.
Some tourists, stunned to see a bison or bear in real life, literally stop in the middle of the road or on blind spots on the side of the road and cause accidents. Head to designated pullouts where you can safely take pictures. And do stop if you see a bear crossing the road. They have the right of way.
Sunny summer weather can turn dangerous quickly in Colorado's mountains.
Rocky Mountain National Park via KDVR/KWGN
Drink enough water. Whether you're hiking down a mile into the Grand Canyon or trekking in Death Valley (known as the hottest and driest place on earth), carry and drink enough water to stay healthy. Death Valley offers instructions to drink plenty of water (at least one gallon per day), avoid hiking in the heat and travel with survival in mind (bring extra water for unforeseen events such as a car breakdown). Pay attention to the weather. Shorts may seem like the obvious choice for a sunny day hike at Rocky Mountain National Park, but the weather can turn wet quickly and lightning can strike before you know it.
Start your hikes early in the day, dressed in layers, to finish before summer storms come through the mountains. (Rolling clouds and distant thunder can be a sign to head down the mountain.)
You might see summer snow still slowly melting at high elevations, so make sure it's on solid ground before stepping on it. And make sure to adjust to the high altitude (and talk to rangers about avalanche safety) before heading into Colorado's beautiful mountains.
Wear the right clothes. Layers, layers, layers. If you're hiking where the weather can get cold quickly, dress in layers. If the heat is deadly, hike before it gets too hot, protect yourself from the sun or schedule your trip during a cooler time of year.
You can safely get great photos by following these guidelines. Read more about getting smart shots at the National Park Service website and at individual park sites.