The Fairbanks Daily News-Miner reports the North Pole man told authorities he shot the bear after it charged his girlfriend while the two were hiking up Tattler Creek on May 28.
"We can't say they did anything deliberately wrong," Parks spokeswoman Kris Fister said.
Fister said the evidence collected by rangers is consistent with the description of the incident. She added the man's name was not released because he was not charged with a crime.
The shooting is believed to be the first time a hiker fatally shot a bear in Denali. The shooting happened three months after Congress approved a law allowing people to carry loaded guns in national parks.
It's still against the law to actually fire a gun in the part of the park where the bear was shot, but Fister said park officials determined "this was a legitimate defense of life" and decided not to press charges.
Fister said the area where the shooting took place is known to have a lot of bears. She said the couple was hiking when the man heard a noise in the brush. He turned, drawing his .45-caliber, semi-automatic handgun from a holster on his waist moments before a large grizzly bear emerged and charged the woman.
The man fired seven to nine rounds, stopping the bear. The couple then notified park officials.
Rangers found the bear dead the next day. It was a 434-pound male.
Fister said park officials aren't worried more people will use guns now that the new law has passed. They do caution that guns don't necessarily mean safer hikes.
"You can't depend on those," she said. "We hope people are still going to realize the use of firearms or bear spray is only potentially appropriate in a very last-ditch effort, and they need to take precautions. If someone doesn't how to use it well, you can tick an animal off and create a worse situation."
Important warning about e-mails purporting to be from the adn.com staff.