Officials in Boone County said a 17-year-old boy who has autism was found safe hours after his family reported him missing.The teen left his home in Union on a mountain bike at around 5 p.m. Monday. His family said he was riding to the Hempsteade Park nearby, but never returned.Just after 11 p.m., the Boone County Sheriff's Office said the boy was located safely in Florence. The Golden Alert is canceled.