The Schaumburg teenager reported missing was found Monday in a hotel near Midway Airport.
Schaumburg police said they found Raquel "Rachel" Bonilla around 2 p.m. Monday at a hotel on the 7700 block of South Cicero Avenue, in the company of a 27-year-old Chicago man.
Sgt. John Nebl said the 16-year-old appeared to be in good condition.
Her family said Bonilla had been missing since Wednesday night, when she did not return from school.
Nebl said police found a notebook in the Schaumburg High School junior's locker, which contained a letter written to Bonilla's mother saying she was running away. That letter was found either Sunday or Monday, Nebl said.
Police were bringing the girl and the man to the Schaumburg police station for questioning.
Nebl said police didn't know how the two knew each other or if any crimes had been committed.
Nebl said police determined Bonilla was near Midway Airport through interviews.