On July 18, 1918, two large bolts of lightning struck and killed 654 head of sheep on Mill Canyon Peak in American Fork Canyon. According to one historical account: "Forked lightning had struck twice and split down two sides of the peak...There was about a seventy-five foot swath in between the dead sheep and where not a one was injured...The dead sheep all had to be moved to the opposite side of the canyon so as to be off the 'water shed.' Men counted them as they were moved, 654 sheep had been killed."