A Montana wilderness guide has died days after being attacked by a grizzly bear near Yellowstone National Park, officials said, the New York Post reported.

Carl Mock, 40, suffered a massive stroke and died, two days after a bear weighing at least 420 pounds (about 190kgs) mauled him while he was fishing near Baker’s Hole campground, according to an online fundraiser.

Mock suffered severe injuries in the attack and was taken to a hospital in Idaho Falls, where he was set to have several surgeries.

The male bear believed to have mauled Mock was shot and killed by a group of game wardens and ursine specialists, according to department officials.