What if you came in close contact with a pack of grizzly bears: Would you run? Scream? Just stand still and hope for the best?
"My heart was pounding Saturday night, I'll tell you that," Hanna told ABC News' Diane Sawyer.
At around 2 p.m. Saturday, Hanna and his wife Suzi were trekking up Montana's Glacier National Park, a location he said they have frequented for more than 20 years.
As they approached a corner within a section of the park called Grinnell Glacier, the two hikers, along with two other groups of hikers, encountered a mother grizzly and her offspring just 30 feet away.
"Here comes a mama and yearlings, not cubs," Hanna recounted. "Yearlings are about 100 to 150 pounds. You cannot run from these animals. They run a football field in six seconds."
After advising the other hikers to slowly walk back on the six-foot-wide trail for what "[seemed] like an hour," and also taking into account the cliff with a 1,000 foot drop on their other side, Hanna knew that his pepper spray eventually would be their ticket to safety.
But before Hanna even drew his can, the mother and one of the yearlings passed by, leaving the other just 10 feet away. It was not until the bear started getting closer to the hiking group that Hanna took action and sprayed the animal.
"I unloaded the first blast and the wind blew the damn pepper spray right away," said Hanna. "He's still coming, so I blast him again about 15 feet and he's still [coming], 'roar', and he goes like that about 10 feet right in front of me. I had the pepper spray right in his face. I mean, I could just [have said] this is it for me. I just go 'pssssh' and unload the whole thing in his face.
"That's why I waited so long for that first blast of pepper spray, because I didn't want that yearling squealing for his mom, and the mom comes back and [says], 'I'm going to kick somebody's butt here,'" Hanna said. "I didn't want it to be my butt."
Interestingly enough, Hanna said he recorded a public service announcement for the National Park Service just two weeks ago. The governmental organization even has a video in which it informs potential visitors of what to do should they encounter a bear.
If anything, hikers are advised to carry bear pepper spray, which is non-toxic and non-lethal and is in a larger canister than "human" pepper spray.
Groups also are told to only use it if the bears are aggressive, but are advised not to spray their camp area with the aerosol.
Groups also should take into account the distance at which they are spraying as well as the surrounding weather to determine its effectiveness.
If the pepper spray doesn't work, Hanna said, hunker down and brace yourself. It is advice that has been successfully used on the same trail before.
Also, the National Park Service suggests that people get in either a fetal position or turn sideways to assume a non-threatening stance.
"What you don't want to do is run," Hanna said. "You put your arms in front of your face and protect your face. They'll bat around you and bite you, and then they're going to leave you alone. They're telling you to stay away. They're not trying to eat you."
Grizzlies spend their days eating berries, grass, moles and bugs instead, he said.