The girl was riding a long board behind Deerfield Elementary school early when police say an adult male exposed himself.
The girl ran back the way she had come and says the man ran in the opposite direction.
Police say the man is a short, bald, white male. Police also say he was wearing dark shorts and no shirt at the time of the incident.
Anyone with information is asked to contact the American Fork Police Department at 801-763-3020.