Barrie Gilbert was walking fast on a treeless, 9,200 foot ridge in Yellowstone National Park almost exactly 20 years ago, seeking a high perch where he could watch for bears with his binoculars.

Earlier on that morning of June 27, 1977, he had seen grizzlies, but he believed he had climbed above their normal stomping grounds and didn't expect to find any on the ridge.

He was wrong.

Suddenly, a bear appeared, rising from a day bed.

Gilbert ran, hoping that putting distance between him and the bear would diffuse the charge.

He was wrong again.

The bear was on him fast, crunching its teeth into the back of his head, tearing the scalp from his skull and mauling his back.

Then Gilbert rolled over and tried to fight. The bear tore off much of the left side of his face, including an eye.

He was scalped, his nose was crushed. His ears were detached, and his brain was exposed to the open air. One of his graduate students, who had been following him up the mountain, found the bear on top of Gilbert and was able to scare it away and summon help.

A helicopter carried him off the mountain but it took 11 hours of surgery and two months in the hospital to put him back together. And he will carry the scars forever.

If anybody has a right to hold a grudge against grizzly bears, it's Gilbert.

But that's not the way it worked out.

Instead, Gilbert has dedicated his professional life to studying and protecting grizzlies. He's a passionate advocate for keeping bears alive and giving them room. And he spends as much time around wild grizzlies as he can, perhaps as much as anybody alive.

As a research professor of animal behavior and wildlife management at Utah State University, he focuses his studies in Alaska and Canada. Over the past 25 years he has become a noted authority on how to manage people and bears when large numbers of both come together.

That means he spends a lot of time in places like Alaska's Katmai National Park, which has the highest density of grizzly bears in the world, a place where people and bears often spend hours within 20 yards of each other.

He's appeared in a National Geographic documentary, speaking out for the bear, and has written in both academic and popular journals about grizzlies. He's a fixture at national and international bear conferences.

Last week in Bozeman, at a meeting that attracted bear managers, biologists and advocates from around the region, he urged the U.S. Fish and Wildlife Service, the National Park Service and the U.S. Forest Service to set aside more room for bears in and around Yellowstone.

He urged them to work harder to counteract all the negative factors the roads and the numbers of people that are harming bear habitat. Shut down backcountry roads and keep people out of areas where bears are active, he said.

Cattle have eliminated many berry producing shrubs that bears depend on, Gilbert said. Move the cattle out and plant more shrubs.

Think about giving bison and elk carcasses to bears instead of to hunters, he argued.

"They need the food and we don't," he said. "It's crushingly depressing to see how little we do for the bears. In less than 200 years, we've been able almost to blink them out. Why is that?"

Gilbert isn't the only one saying what he's saying. Other scientists back him up consistently. But Gilbert's injuries give his statements more authority, according to people who know him.

Many bear biologists and advocates speak with great eloquence about protecting bears and their habitat.

"But they don't know the reality of being on the ground with a dangerous bear," said Doug Peacock, a writer and bear advocate who is working with Gilbert to preserve some prime grizzly habitat in British Columbia. "I think he's much more powerful than he even knows."

Gilbert downplays the significance of his injuries and prefers to talk about bears instead of himself.

He has plenty of advice for hunters moving quietly in grizzly country. First of all, pay attention. Pretend you're a carnivore; look ahead and use your eyes and your nose. And understand that you don't have to use your gun as a first resort.

Bears aren't looking for a scrap, he said, and will avoid you if they can. In his case, the mauling came after "a classic surprise encounter. Both of us would rather have been someplace else."

Carry pepper spray in bear country, he advised. It may or may not deter the bear, but it changes human behavior because it gives people the illusion they have a weapon.

"You think you're armed," he said. "And it's a huge psychological disadvantage, being face to face with a bear with no weapon."

Grizzlies are incredibly strong. They've been known to kill grown steers with one swat, dislocating so many ribs that the animal dies of shock.

The bear that mauled Gilbert could have killed him in an instant but chose not to.

Because he was moving quickly toward the bear when she spotted him, "I think she thought I was charging."

She bit him on the head and face, he said, "because she wanted to neutralize my weapons. She thought I had big teeth."

For many people, injuries like Gilbert's would fill them with loathing of bears, Peacock noted.

"But he loves this animal," Peacock said. "That is not lost on people. It's certainly not lost on me."

He praises Gilbert for his scientific integrity, for his strenuous efforts to retain his independence.

His scars add weight to his words, but Gilbert tries to steer conversation toward the bear and away from himself.

Keeping wild grizzlies alive in the lower 48 states for future generations is no easy task, he says, and will require a lot of compromise from people.

He isn't sure it's possible, though. Most people like the idea of saving bears, but if it means things like losing a favorite campsite, handling your cattle differently and changing how and where people hunt, the compromise may be impossible.

"American society has no respect for native people and no respect for native animals," he said, a little sadly. "We're an avaristic society that wants it all."