A fatal bear attack in a Montana campground near Yellowstone National Park prompted a flurry of concerned phone calls to the park this week, but bear attacks are far from the most common danger to park visitors.

In fact, there hasn't been a bear mauling in Yellowstone since 1986,  said Yellowstone public affairs officer Linda Miller.

Motor vehicle accidents may be the most common way people are killed or injured in national parks, said Gerry Gaumer, deputy chief of public affairs for the National Park Service (NPS).

"People are looking at things other than the road," Gaumer said. "They're sightseeing. Even though the speed limits are lower in the parks, these are mostly two-lane roads."

"We have lots of traffic accidents every day," Miller said. She estimated that there are about three "life-flights" to transport a person out of the park to a hospital every day during the busy summer months. "They're mostly because of car accidents and medical problems, like heart attacks. Animal encounters are rare."

Indeed, medical problems rival car accidents as a cause of death in the parks. In Yellowstone, of the 61 fatalities that occurred in the park from 1998 to 2006, 23 were due to either heart attacks or diabetes.

Twenty deaths within Yellowstone during those years were due to motorvehicle accidents, but the park-reported numbers do not include people who transported out of the park after an accident who later died of their injuries once off-site, Miller said.

Although the total number of fatalities that occur every year in the parks is generally low, Gaumer said, suicides are another common cause of deaths.

"They are remote areas – no one will stop you," Gaumer said. In particular, Colorado National Monument seems to have had "more than their fair share" of suicides, but the number that have occurred there could be counted on one hand, he said.

One man died by suicide in Yellowstone earlier this summer, Miller said.

Bear attacks on people in the parks are very rare. For example, nearly 2 million people now annually visit Waterton-Glacier National Park, in Montana and Alberta, but only 10 bear-related fatalities have been reported in the park since Glacier opened in 1910.

How to prevent bear attacks

The best way to reduce the risk of a bear attack is to take proper precautions, according to the NPS. Black and brown bears can swim, climbtrees and run faster than people – both can hit top speeds of 35 mph (56 kph) or faster.

Although pepper spray may be a useful safety device and has been shown to be effective at deterring grizzly bears more than 90 percent ofthe time, it could also give people a false sense of security, according to the NPS.

Being alert to one's surroundings and making noise to avoid surprising a bear lower your chances of an attack. Because both black and brown bears tend to investigate human items such as food and garbage, it’s a good idea to secure all gear. People should never approach bears,according to the NPS.

And it is only in extremely rare cases that a bear will attack at night or after stalking a person, according to the NPS. This situation is very serious, because it means the bear is preying on people for food. A person in this situation should act in ways that let the bear know that they are not prey – shouting and shaking a branch or throwing arock may help.

This article was provided by Life's Little Mysteries, a sister site to LiveScience.