A six-year-old male grizzly bear was captured and destroyed after a run in with two hikers on the Mount Fairview trail near Lake Louise.

According to a Parks Canada release, resource conservation personnel put down the bear because the animal’s behaviour had become increasingly aggressive and it presented "too great" a threat to the public. The most recent encounter took place Monday.

Canmore mountain guide Barry Blanchard was guiding a Japanese tourist when the big grizzly started to follow them. The pair eventually dropped their packs and started to climb the closest tree.

Blanchard said he soon heard the bear ripping apart their packs.

"I quit hearing the pack rip apart noises and I felt the tree start to vibrate and I immediately knew the bear was coming up," he said.

Blanchard said they climbed up as high as they could, but so did the bear — close enough that he was eventually staring into its eyes just metres below.

"I heard him panting and he stopped," said the guide, adding he pegged the bear at around 180 kilograms. "I think it was quite hard work for him."

The animal apparently changed its mind and went back down the tree but stayed in the area. Blanchard said the overall two-hour experience was terrifying before they were escorted out by a conservation officer.

The collared bear had been known to wildlife managers and Parks Canada said hundreds of hours and resources went into giving it the best possible chance of survival in the national parks.

The department says this was the first grizzly bear destroyed in Banff, Yoho or Kootenay National Parks since 1995.