The black bears of Yosemite National Park are no longer waltzing into campsites, breaking into cars and scarfing tourist food with impunity under the majestic granite domes and soaring waterfalls.

Hungry bruins were responsible for only 76 aggressive or destructive incidents in the park this year — the fewest since record-keeping began in 1975, Yosemite officials said Thursday. None of this year’s incidents involved injuries.

That’s compared with some 1,600 bear-human incidents recorded in the peak year of 1998, a 95 percent decrease.

“We’ve made a lot of headway, but I don’t think this problem is ever solved,” said Caitlin Lee-Roney, a wildlife biologist for the park.

Lee-Roney and others remember the bad old days when the ungainly brutes lumbered around Yosemite Valley like they owned the place, prompting a nightly chorus of banging pans, flash grenades and yelling among campers in Curry Village.

At times in the 1990s, 10 to 15 cars would be ransacked in a night. In 2000, bears broke into more than 300 cars, often roughly clawing them open. Later, a study revealed the animals had begun associating minivans with grub, ripping into them more often than other vehicles.

This year, only two cars were broken into, Lee-Roney said. Property damage from bears in general was down 99 percent from the peak. And, officials said, most of the damage was minor— a sandwich here, a backpack there.

With declines over four straight seasons, officials are crediting a major public information campaign focused on keeping food securely locked away.

Educating the public

The National Park Service has invested in bear-proof storage lockers at campgrounds, parking lots and trailheads. Videos and literature handed out to visitors coach the importance of keeping food out of cars and tents and away from animals.

The nonprofit Yosemite Conservancy has also provided $2.1 million since 1989 for bear management, including $70,000 to outfit problem bears with GPS collars that allow rangers to track their whereabouts.

American black bears, known scientifically as Ursus americanus, are not normally aggressive toward humans — no one has been killed by one in California in at least a century — but they love people food, especially in the late summer and fall. Lee-Roney said the animals eat up to 20,000 calories a day as they bulk up for winter hibernation.

They are also curious, incredibly intelligent and have a strong sense of smell.

“They are eating machines, especially in the fall, so if there is food available they are going to change their behavior to get it,” she said.

Bear encounters have been an issue across the state.

Part of the problem, according to experts, is a steadily growing black bear population in California. In 1984, there were 4,080 American black bears in the state, but the count now stands at about 40,000, according to wildlife officials.

More bears means more cubs and, as the bruins compete for food to feed their young, more home invasions and garbage raids.

The Lake Tahoe area, where 350 or so bruins compete for food, is another area where unruly bears have made themselves known. The bears there rarely hibernate, especially during drought, and tend to be more aggressive. They have been known to smash windows, yank doors off their hinges and enter homes and businesses where food might be stored.

Rogue bruin

In 2010, a gigantic, bullet-scarred black bear terrorized homeowners on the north shore of Lake Tahoe, deftly outmaneuvering gun-toting rangers, bear dogs and traps.

The large number of bear break-ins over the past few years led to a surge in exterminations and, it is believed, a good many orphaned cubs.

In most cases, people are the problem. The California Department of Fish and Wildlife and other agencies have in recent years cracked down on those who would feed the beasts, including a Mendocino County woman who transformed her home into a bear wonderland, with wading pools and specially prepared banquets of corn meal and peanut butter sandwiches.

“If we stop educating the public about food storage,” said Lee-Roney, “the problem would come back.”

Peter Fimrite is a San Francisco Chronicle staff writer. E-mail: pfimrite@sfchronicle.com