The strike occurred saturday night at the Katahdin Stream Campground.
Park officials say 24-year-old Evans Huber was camping with his mother and 18-year-old brother when lightning struck a tree near their campsite.
Energy from the bolt jumped off the tree and struck Huber as well as his brother, Emmett.
Park officials were called to try and revive Evans, but he was pronounced dead at the scene.
The younger brother was taken to the hospital with first and second degree burns on his feet. there has been no word on his condition.
The mother was not injured.
This is the third lightning-caused fatality in the park’s recorded history.