Growly was the scourge of Glacier. In the late 1970s, the adolescent male grizzly bear tore through Montana’s Glacier National Park, clawing up cabins and campgrounds until he was captured and relocated by park rangers, at which point he’d crawl his way back to civilization to execute another round of property damage. In 1977 the delinquent bear was slated for “destruction” when a zoology student at the University of Montana offered him a new home. For three days Growly languished in a tiny cement block chamber at the northern edge of Manitoba, Canada. Then the experiments began.

Growly—then 7 years old and weighing in at more than 400 pounds—had been brought in to test dozens of strategies for defusing human interactions with bears like him. Under the supervision of zoologist Gary D. Miller, a research assistant stood outside a barred door to Growly’s chamber and presented a range of unpleasant stimuli to the captive bear. They played recordings of growling bears and hissing humans. They blared boat horns, blew whistles, engaged strobe lights, and set off firecrackers. Finally, they sprayed chemicals directly into the bear’s face: onion juice, Windex, mustard, and an aerosol-based dog repellent called Halt.

The ominous recordings failed to produce a consistent reaction from Growly. When the researchers rang small bells—then sold to hikers in Glacier to warn bears of their approach—Growly slept through the test. Twice. Deploying the boat horn managed to stop Growly midcharge, but it didn’t turn him away. The explosive sounds of a firecracker and a dart gun sent Growly scrambling away from the door—for a time. But the dog spray produced the most dramatic and long-lasting results. When the assistant appeared, Growly would charge toward the chamber door. Then he got sprayed in the face with Halt, at which point he’d hightail it to the opposite corner of the chamber, rub his eyes with his paws, and strenuously blink.

Miller concluded that the chemical spray—which “caused immediate, intense pain” upon eye contact—made for a highly effective deterrent. Just increase the dog repellent’s range to fit that of a full-grown grizzly, he suggested, and you might be able to prevent a mauling. Once the experiments were over, Miller brought in another grizzly, Snarly, to repeat the tests (followed by two female polar bears), and Growly was shipped off to the Columbus Zoo, where he lived in isolation until he was finally euthanized in 2002. He died an unsung hero: By getting maced in the face in a concrete box, Growly may have helped save countless fellow bears from an even direr fate.

From the perspective of the grizzly bear, people are the ones who constitute the aggressors in the outdoors. Though bear attacks are rare—fewer than three people are killed by bears in North America every year, and a visitor to Glacier is more likely to be injured on the car ride over than swiped by one of the park’s furry residents—they typically arise when a bear feels provoked to protect its cubs or its food, or when it’s unexpectedly startled. The best method of preventing a bear attack is to stay the hell away from bears and the places they go, like salmon streams, heavy-duty brush, or berry patches. (Last week a Montana man was mauled by a grizzly while hunting black bears—come on.) Should human-ursine paths cross, careful attention to bear behavioral cues can help both parties walk away unharmed, no weapons necessary. But when a grizzly charges, a commercial bear spray is now the hiker’s, hunter’s, and bear biologist’s backwoods protection method of choice. Dingly little hiking bells are but a quaint relic.

“I’d rate the effectiveness of bear spray at a 10 out of 10,” says Chris Servheen, the Grizzly Bear Recovery Program coordinator for the U.S. Fish and Wildlife Service. “I carry it myself.” And there’s reason to believe that bears appreciate it, too. Sure, it stings. But it beats a bullet in the head from a wandering hunter—or else getting slated for “destruction” by park bureaucrats who are forced into action after a bear mauls a person. Recent studies suggest that the spray is safer than bullets for both human and bear: In 2012, University of Calgary bear authority Steve Herrero examined hundreds of incidents of human-bear aggression and found that 98 percent of people who deployed bear spray were unharmed by their bear encounter (and no humans or bears died). Meanwhile, 56 percent of people who raised a gun to a bear were injured, and 61 percent of those bears were killed. “If you use bear spray, you and the bear walk away from this encounter alive,” says Ryan Scott, a wildlife biologist for the Alaska Department of Fish and Game’s Division of Wildlife Conservation. “If you use a firearm—even if you do it totally accurately—the bear’s going to be dead. And once you start shooting, you need to finish the job.”

The unrivaled success of bear spray since Growly’s 1977 trials is the result of both a highly effective product and a grisly marketing scheme. Bear spray companies use demonic images of bears and harrowing testimonials to compel people to pack their products in the outdoors. In 1977, William Pounds unwittingly set up camp in the middle of a Montana huckleberry patch and awoke to the outline of a bear’s gigantic, panting snout pressed against his tent. He escaped unscathed, but the close encounter became his go-to scary story when he began marketing Counter Assault—a highly concentrated, aerosol-packed irritant derived from hot chili peppers that bills itself as “your ultimate protection in the wild”—in 1986. (And Growly’s legacy now extends beyond the forest: In the early ’90s, Counter Assault started packaging its spray in smaller cans for street use against other humans, and pepper spray soon began replacing tear gas canisters in cops’ belts).

UDAP, Counter Assault’s central competitor on the bear spray market, was built on a more gruesome tale. While on a bow-hunting trip near Yellowstone in 1992, Mark Matheny came across two grizzly cubs on a trail and was promptly charged by their mother, who crunched Matheny’s face between her jaws and tore at his arm until a friend sprayed her with a relatively mild human pepper spray called Karate in a Can. “I remember seeing those little black, beady eyes,” Matheny recalls on UDAP’s website, where he recounts the entire story next to blood-splattered photos of his post-attack frame. In the light of the mauling, “I became obsessed with the subject of pepper spray as a bear deterrent to stop this kind of an aggressive attack,” Matheny writes. He took a job as a salesman for a bear spray company, but dreamed of a spray that was hotter, longer-lasting, and packed in a can that glowed in the dark for easier access at night. In 1994 he founded UDAP in a bid to build a better bear spray. “I didn’t invent the wheel,” Matheny says. “I just improve it.”

These days, there’s not much left to tinker with. “Bear spray is small and feasible to carry. It’s easy to learn how to use. And it works. All of those things combined make it a really valuable product,” Servheen told me. Plus, the typical $40 price tag “beats the cost of being mauled by a bear.” The product’s downsides—bears can be attracted to the residue left behind after the spray settles; if deployed incorrectly, the spray could attack the human’s face instead of the bear’s; and it’s still barred in some parks, like Yosemite, and can’t be taken on planes in either checked or carry-on luggage—are relatively minor.

And yet, the market dominance of bear spray hasn’t stopped modern inventors from attempting to think up superior alternatives. To wit:

*In 2006, Gregory Rondinone filed a patent for a knife fitted with a compressed gas chamber that would allow the user to stab a wild animal and then pull a trigger to launch the blade deeper into its body. Rondinone billed it as “useful in wilderness areas having aggressive animals, such as bears.” (“Such a thing would be crazy,” Servheen told me).

*In 2011, Donald Spearman filed a patent for an alternate deployment method for bear spray in which a balloon filled with spray is attached to a hiker’s back via a belt, allowing the user to pull a trigger, pop the balloon, and spray the bear even if she is currently facedown “on the ground being mauled.” (There “remains room for variation and improvement within the art,” Spearman wrote. Indeed: That same year, a pair of inventors filed a patent for a bear spray that could be lodged in the hollow of a hiker’s walking stick.)

*In 2003, brothers Adam Bell and Victor Saunders filed a patent for an inflatable shell that can be worn on a hiker’s back, then instantly blown up into a large, frightening pop-up figure “meant to scare away an attacking or aggressive animal such as a bear,” the patent application reads. The inflatable pop-up doll would be designed to look like a bear itself, the inventors add—perhaps with plastic “arms raised in the classic attacking bear posture,” or painted to show “teeth bared, claws extended and nostrils flared.” Bell, a California patent attorney, told me that Saunders conceived of the product after encountering bears while scaling mountains around the world, and they’ve tested a prototype on house pets to impressive results. “The poor cat almost had a cardiac arrest,” Bell says. “I couldn’t find her for two hours.” (It’s not a bad idea: Bears can be deterred by the presence of “something big that looks more impressive to the animal,” Servheen says; Growly even responded favorably—that is, he retreated—to a research assistant holding up a big piece of plywood in front of his chamber door. Then again, if the bear isn’t scared away by the popup’s initial deployment, you can’t go back and scare it again. With bear spray, you can keep spraying.)

*After a 1984 encounter with a British Columbia grizzly, eccentric inventor Troy Hurtubise began developing a personal suit of armor he calls the “Ursus Mark,” a metal exoskeleton that makes him look like a Transformer and that he says will help would-be grizzly researchers get mauled by bears without sustaining serious injury. (Hurtubise has failed to parlay his armor suits into commercial success. “I’m not sure we’re all going to be lurching around like space robots anytime soon,” Servheen said. “Bonk-bonk.”)

Why are inventors still trying to resolve the dangerous potential of human-bear interactions, when a perfectly good solution is already bottled in a can? “There are a lot of people who are just kind of out there,” Servheen shrugs. But bear deterrents have always been built on a mix of sound animal science and complicated human psychology. Perhaps surviving a run-in with a bear is such a rare and horrific event that it can compel a person to put his unique experience to productive use—to even become “obsessed,” as Mark Matheny put it, with conquering nature through innovation.

In 2010, Tim Scott earned the dubious honor of surviving the first-ever recorded bear attack in the state of Kentucky after a young, 200-pound male black bear sighted Scott on a trail, “looked straight into my eyes,” stalked him with precision, and gnawed at his legs until another group of hikers walked up and scared it away. Scott recovered in six weeks, but the bear’s piercing look lingered in his memory. After the attack, Scott turned down interview requests from lurid nature shows that hoped to exploit his experience to paint a horrific portrait of bears in the wild. (“I don’t want to be involved with anything that’s prejudicial to bears,” Scott told me. “I’m a proponent of bears. I like bears. I like them being in the wilderness.”)

Instead, Scott conceived of an intense version of a hand-held laser pointer that might distract an aggressive bear when shone directly into its eyes. Scott read up on bear psychology, interfaced with bear biologists and physicists, and, in 2011, filed his patent for the bear dazzler, which “produces eye irritation in an animal” without the need for a short-range chemical spray. Scott is still hoping to test the device, but in the past few years, city life’s gotten in the way. When he does bring his laser into the wild, Scott says he’ll need access to “a bunch of bears,” he says, along with alternate means of protection in case his laser doesn’t cut it—including, naturally, some trusty bear spray.