10 of the Most Dangerous Spots in the U.S. National Park System

A hiker walks through knee-deep water in a sandstone canyon
The Narrows, a famous slot canyon in Zion National Park, can be overrun by floodwaters triggered by faraway storms.

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Every year, America's 63 national parks and 360 national monuments, parkways, battlefields, and other park units play host to hundreds of millions of visitors. These popular natural attractions are not dangerous on the whole, but there are more than 300 deaths inside U.S. parks each year on average. Most of these fatalities are due to drowning, car accidents, or falls. Injuries and deaths from incidents like grizzly bear attacks or snake bites, meanwhile, are rare. Some of the most dangerous sections of national parks are in remote wilderness, and few visitors ever set foot there. Other deadly spots are easily accessible and well-trafficked. 

From volcanoes in Hawaii to mountain peaks in Alaska, here are 10 of the most dangerous spots to visit in national parks.

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Hawai'i Volcanoes National Park (Hawaii)

Molten lava flows into a body of water, creating steam

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Volcanoes National Park, on the Big Island of Hawaii, features active volcanoes. The most active, and most visited, is Kīlauea, which has been erupting almost continuously for more than 30 years. It also has a history of more violent eruptions, with one occurring in 1790 that killed hundreds of people.

The park has more than 100 miles of hiking trails, with some that lead visitors past old lava fields and near the active eruptions. But one of the biggest dangers in the park is noxious gases. Vog, a mixture of sulfur dioxide and other gases emitted from a volcano reacting with oxygen, can exacerbate symptoms in people with respiratory or vision problems. 

The park also features peaks that rise to more than 13,000 feet above sea level, and altitude sickness is a real danger, especially for people who drive from low elevations without taking time to adjust.

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Precipice Trail, Acadia National Park (Maine)

A young girl climbs up a rock face on a cliff above a blue lake

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Precipice Trail clings to the side of Champlain Mountain in Maine's Acadia National Park. Champlain is only the seventh tallest peak in Acadia, but the 2.5-mile path to the summit stands out as a dangerous climb. Iron rungs, handrails, and ladders help visitors climb vertical sections of the trail, which ascends 850 feet.

The National Park Service issues weather advisories because winds, rain, and snow can make the hike extremely treacherous. Though most people can navigate the route successfully, there have been injuries and deaths. In 2021, the NPS arranged a helicopter evacuation of a man who was unable to continue the climb due to icy conditions. 

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The Narrows, Zion National Park (Utah)

A man stands in a flowing stream in front of a narrow slot canyon

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Zion National Park is deep in the heart of Utah's canyon country, and The Narrows is one of the most dramatic canyon hikes in the park. Beautifully textured, thousand-foot canyon walls attract throngs of hikers every year. Rather than following a defined trail, visitors wade up the canyon through the shallow Virgin River. Trips range from a few minutes to challenging overnight journeys. 

Two-day trips through the canyon require a permit, but hiking any distance can be dangerous. Slot canyons (narrow, water-eroded canyons that can be as little as a few feet wide) like The Narrows are prone to flash floods, which can raise the water level with little warning. Floods can be triggered by storms that are miles away, even when there's no rain in the local forecast. The NPS has safety precautions for visitors, which include checking flood forecasts.

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Mount Rainier National Park (Washington)

A base camp near a rocky mountain peak surrounded by glaciers

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Mount Rainier is a glaciated 14,411-foot peak climbed by more than 10,000 hikers every year. Of those hikers, fewer than 1% reach the summit, which requires technical climbing skills and traveling over avalanche-prone snowfields. 

Many visitors decide instead to take day hikes up to Camp Muir, which is the base for trips to the summit. This hike is still strenuous, requiring an ascent of 4,660 feet. The danger comes when hikers and climbers are hit with surprise storms, which are common in this region. The coastal areas are known for their rains, which turn to heavy snow at higher elevations. More than 400 deaths have occurred on Rainier, and most are caused by exposure and hypothermia during storms.

Mt. Rainier is also an active stratovolcano—a tall, conical volcano marked by explosive eruptions—that last erupted in 1894. It is one of the 16 Decade Volcanoes, historically violent volcanoes that are near large population centers. 

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Bright Angel Trail, Grand Canyon National Park (Arizona)

A string of mules traveling along a narrow path above the Grand Canyon

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The Bright Angel Trail is a steep, narrow trail that takes hikers to the bottom of the Grand Canyon. Over the 10-mile journey, the trail drops more than 4,000 feet along a rocky path only a few feet wide. It is possible to hike the trail, but traveling down on the back of a mule is more common. Hikers and mule trains passing one another on the narrow trail can be dangerous. The NPS has reported injuries to hikers and fatalities among mules during such encounters.

The narrow trail is hazardous, but the true danger in the canyon is the heat. The daytime temperature can reach 120 degrees. Between 2011 and 2015, park rangers assisted more than 300 hikers every year, with a marked increase in incidents when the temperature was above 100 degrees. In the summer, rangers suggest starting hikes before dawn or after 4 p.m. to minimize exposure to dangerous temperatures.

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Blue Ridge Parkway (North Carolina and Virginia)

Cars travel along a windy, mountain road amidst trees with yellow leaves

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Law enforcement rangers on the Blue Ridge Parkway, the busiest road in the National Park System, respond to more than 200 traffic accidents every year. About half of these incidents result in serious injury or death. With tight corners and narrow shoulders, driving on the parkway requires attentive driving. The NPS has constructed more than 250 overlooks along the 469-mile parkway for visitors to enjoy views of the Blue Ridge mountains safely. Speed limits along the road range from 25-45 mph to ensure driver safety, as well.

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Half Dome, Yosemite National Park (California)

Cables ascending a granite monolith against a blue sky

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Since 1930, 23 hikers, rock climbers and base jumpers have lost their lives on Half Dome, the impressive granite monolith that rises 5,000 feet above the valley in Yosemite National Park. The vertical rock face, usually only attempted by technical rock climbers, is the most deadly, resulting in 36% of fatalities on Half Dome. Most visitors instead reach the summit by way of a strenuous 14- to 16-mile hike. This route, while not as challenging, has also caused five deaths.

The final 400 feet of the trail ascends a steep, bare rock face, which has been equipped with cable handholds to aid hikers climbing to the summit. In 2010, the NPS instituted a hiking permit lottery system for the cable section, to ease safety concerns about overcrowding.

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Death Valley National Park (California)

A rocky, expansive salt plain in Death Valley National Park

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Death Valley National Park is the hottest and driest place in the United States and the location of the highest recorded temperature worldwide, which registered at 134 degrees. Every year, the park also sees more than one million visitors, and heat-related illness is one of the leading causes of death in the park. The NPS recommends finishing hikes by 10 a.m. to avoid dangerous temperatures. 

Getting lost in the desert is also a danger. Park rangers recommend following a route on a paper map, rather than relying solely on GPS, which can negatively impact memory during self-guided navigation. Vehicles should also be outfitted with extra water in case of a breakdown.

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Lake Mead National Recreation Area (Nevada and Arizona)

A boat travels across a blue lake in a desert environment

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Lake Mead National Recreation Area is home to Lake Mead, the largest human-made reservoir in the country. Lake Mead is the cause of more drowning deaths than any other location in the park system. From 2007-2018, there were 89 drowning deaths here, almost double the number in any other park. Nearly all of these drownings can be attributed to not wearing proper safety equipment, and park rangers at Lake Mead have started life jacket loaner programs to combat these preventable drowning deaths.

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Denali National Park (Alaska)

Mount Denali dominates the landscape on a clear day

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Mount Denali, the centerpiece of Alaska's Denali National Park, is the tallest and coldest mountain in the United States. Avalanches, extreme cold, and blizzards on the 20,308-foot peak have killed more than a hundred climbers over the decades. With most summit expeditions lasting several weeks, climbers are exposed to the harsh conditions for days on end. Only 52% of the mountaineers who set out for the summit reach their goal, with the remainder turning around due to weather or other hazards. 

weather station installed near the summit in the 1990s puts the extreme cold into context. The lowest recorded temperature at this location was -75.5 degrees, with a windchill of -118.1 degrees, in December 2003.