The man's name is being withheld pending notification of his family, park officials say.
The tourist was part of a group enjoying a summer hike on the well-known Fairy Falls trail, just north of the Old Faithful area and west of the Grand Loop Road.
The 36-year-old man left the main trail and was climbing a slope Monday afternoon when a dead lodgepole pine tree that was among a slew of trees killed during the park's 1988 fires fell and struck the man on the head.
Others on the hike who witnessed the falling tree at Yellowstone returned to the trailhead and told two park maintenance workers what had happened.
The workers relayed the information to Yellowstone law enforcement rangers who immediately rushed to the scene.
— Billings Gazette (@billingsgazette) June 10, 2014
The victim was taken by the rangers to the trailhead to meet a helicopter that would transport him to a nearby medical facility. However, attempts to revive the tourist failed, and he was pronounced dead at the scene.
Weather conditions at the time of the accident were windy, according to Yellowstone rangers who responded.
The incident is under investigation by the National Park Service.
Image via Wikimedia Commons