The hollows
(Book)

Series statement from author's website.

"Ohio, 1926: For many years, the underground railroad track in Moonvale Tunnel has been used as a short cut through the Appalachian hills. When an elderly woman is killed walking along the tracks, the brakeman tells tales of seeing a ghostly female figure dressed all in white. Newly elected Sheriff Lily Ross is called on to the case to dispel the myths, but Lily does not believe that an old woman would wander out of the hills onto the tracks. In a county where everyone knows everyone, how can someone have disappeared, when nobody knew they were missing? As ghost stories and rumors settle into the consciousness of Moonvale Hollow, Lily tries to search for any real clues to the woman's identity. With the help of her friend Marvena Whitcomb, Lily follows the woman's trail to The Hollows - an asylum is northern Antioch County - and they begin to expose secrets long-hidden by time and the mountains"--,Provided by publisher.