Bear attacks horrify us, and yet they also, in a morbid way, fascinate many. They're evidence that even in today's modern world tragic confrontations with nature do occur and, in the case of bears, demonstrate that man is not always the apex predator.

This past summer, for the first time to the best of park officials' knowledge, there were two fatal maulings of hikers in Yellowstone National Park by grizzly bears. They followed a year, 2010, in which there were two other fatal maulings just outside Yellowstone's boundaries.

Scott McMillion, a Livingston, Montana-based writer, long has been chronicling bear attacks. His book, Mark of the Grizzly, first arrived in bookstores in 1998. He recently updated it to include the fatal mauling of Erwin Frank Evert in June 2010 in the Shoshone National Forest just east of Yellowstone, and to examine the maulings a month later of campers in a Forest Service campground also just outside Yellowstone's northeast entrance.

Another new chapter looks at "bear whispers," individuals such as the late Timothy Treadwell who come to believe they can establish special relationships with bears. There's also new material on mountain biking and trail running in grizzly country, and a chapter on "dinner bell" grizzlies, bears that have come to connect rifle shots with meals. Sometimes the hunters get in the way of those bears and wind up dead from gruesome maulings.

Read both Mr. McMillion's book and today's newspaper and magazine headlines and the impression quickly bubbles to the surface that there are places in the country that are growing wilder as the years go by, not tamer. Part of the reason behind the attacks is simple numbers, he believes.

“There are more (maulings) than there were 20 years ago," Mr. McMillion said recently, "because there’s more bears and there also are more people going into bear habitat.”

Mark of the Grizzly, much like Stephen Herrero's seminal work, Bear Attacks, Their Causes and Avoidance, will both sate those with ghoulish curiosity about bear attacks and cause some to question the sanity of hiking in bear country. Both also offer lessons to be teased out in terms of making wise decisions in bear country. Decisions that apply both to campers and park managers.

One chapter, Big Trouble in Banff, was in the first edition of Mark of the Grizzly and reappears in the latest edition. It recounts a fateful September 1995 night in a front-country campground at Banff National Park near Lake Louise in British Columbia when a grizzly sow and her cub rampaged through three tents, taking bites out of six campers and their gear.

One of those attacked was Susan Olin, at the time a summer naturalist at Glacier National Park just south of the border. As part of her job, Ms. Olin received lots of training on bears and bear country and how to act in the backcountry. She later recalled in a lawsuit filed against Parks Canada that had she known that there had been bear incidents in the Banff campground just days prior to her arrival -- a bicyclist had chased off one, another bear "had ripped into an empty tent just a day or two before the attack" -- she never would have pitched her tent there.

The problem with the Banff National Park campground, Mr. McMillion says today, is where it's located.

“I think the lesson the Canadians could learn from the American Park Service is don’t develop like that. I think the parks are better off left in as wild a condition as possible," he said, referring to Lake Louise and the nearby town of Banff. "I think it’s the townsite, the ski areas, the attitude of providing entertainment rather than letting people find their own. Do you need to buy a Pierre Cardin necktie in a national park?”

The writer went on to say that the situation in Banff National Park didn't stem from a  "disproprotionate number of bears coming into townsites or campsites." Rather, he said, the developments are smack in the middle of bear habitat.

"They get bears on the golf course there in Banff, and then they’ll wander into town and they’ll have to be chased out," said Mr. McMillion. "It’s the development, which results in the increasing number of people on the trails, on the roads, and that leads to encounters, and those encounters rarely end well. If it is an attack, it rarely ends well for the person or the bear.”

Sadly, while Canadian park wardens gunned down a grizzly sow and her cub the day after the attacks on the campers, they shot the wrong bears. Later it was determined that the ones actually responsible for the maulings had been trapped and relocated sometime afterwards.

The two fatal maulings in Yellowstone this past summer came as the 2nd edition of Mark of the Grizzly was going to press, and so not included in this edition. In the first mauling, which occurred July 6, Brian Matayoshi, of Torrance, California, was attacked when he and his wife encountered a sow with grizzlies while hiking near on the Mary Mountain Trail. The second, which claimed the life of John Wallace of Chassell, Michigan, also took place along that trail, which meanders 21 miles east-to-west through the heart of Yellowstone.

While a park investigation determined that the bear that attacked Mr. Matayoshi was acting defensively to protect her cubs, a final report on the incident that killed Mr. Wallace isn't expected until next month.

Clearly, the Mary Mountain Trail is not in a heavily developed area like the Lake Louise Campground. Sometimes, offers Mr. McMillion, circumstances just place bears and people in the wrong places at the wrong times.

"Almost all bear encounters you can figure out an underlying cause: food-conditioning, surprise encounter, somebody approached the bear, got inside its safety envelope, either accidentally or on purpose. That was a mystery," he said, referring to the maulings in the Soda Butte Campground that left one dead. "Something made that bear snap.”

Mr. McMillion wouldn't be surprised if the circumstances surrounding the attack on Mr. Wallace remain a mystery, as well. Park officials know at least nine bears had been feeding on two bison carcasses nearby, and they tied the sow that attacked Mr. Matayoshi to the area from DNA tests on hair and scat samples collected there. That bear was trapped in late September and killed by rangers; her two cubs were placed in the Grizzly & Wolf Discovery Center in West Yellowstone, a facility that handles bears that get into trouble and would be put down otherwise. However, as of yet park officials haven't said whether they could determine exactly how Mr. Wallace died and whether that bear was involved in the fatal attack.

"It was a guy hiking alone," Mr. McMillion said of the Wallace case. "That one could remain a mystery, too. He may have blundered into the bear. It could have been like Matayoshi; (that bear) nicked the femoral artery. His injuries weren’t that severe. She just knocked him down. They didn’t do a full autopsy, but they said the nicking of the femoral artery, plus just the incredible force of being slammed on the ground caused internal injuries. It wasn’t like she came at him intending to kill. I think she came at him, he ran, and she came at him curious, maybe defensive for her cubs. Boom, just hit him so hard he died almost immediately.”

“It’s unfortunate. All these rules, 'don’t run,' 'don’t fight.' They’re all real easy to say, but they’re hard do," the writer continued. "Sometimes it’s just bad luck. You don’t do anything majorly wrong. A lot of people go out there and do bad stuff all the time, they have dirty camps, bow hunters who are violating all the rules, going through the brush, they’re quiet. They almost always come home OK, but now and then...”

Mark of the Grizzly is not a book for the faint of heart, nor for those filled with trepidation at the thought of leaving a parking lot in Yellowstone, Grand Teton, or Glacier. But it's a powerful book if you're trying to better understand how attacks happen, and what safeguards you can take to better protect yourself against bear attacks.

“I don’t know if they’re becoming wilder," Mr. McMillion responds when asked if these parks are becoming wilder despite an ever-increasing human footprint surrounding them, "but (grizzly bears) are there, and they’re occupying areas where they haven’t been seen for decades."