She was last seen attempting to hitch a ride .
Melissa Smith - The 17 - year - old vanished from Midvale , Utah , on her way home from a night out on October 18 .
Melissa Smith was last seen attempting to hitch a ride .
Melissa Smith - The 17 - year - old vanished from Midvale , Utah , on her way home from a night out on October 18 .