The federal prison camp at Mill Point, Pocahontas County, opened in 1938. The inmates came initially to build State Route 39, now part of the Highland Scenic Highway. Those first inmates lived in tents, and later moved to permanent quarters. Once completed, the camp had a dining hall, dormitories, warehouse, boiler plant, school, administration building, infirmary, sawmill, and craft shop. Near the prison were houses for essential employees, including the warden, electrician, captain of the guards, cook, plumber, and parole officer. Thirty employees ran the prison for 300 inmates.

Sentences ran from six to 18 months at Mill Point Federal Prison Camp. The minimum-security prison on top of Kennison Mountain had no locks or fences, and minimal supervision. Inmates stayed inside the white posts spaced every 40 feet around the perimeter. Escape was as easy as strolling into the nearby woods, but the staff took a head count every few hours. During the years it was open, the prison had only 20 escapes. The inmates included moonshiners and World War II conscientious objectors. It was a curious mix. The well-educated war objectors taught those moonshiners who couldn't read or write.

The prison closed in 1959. The valley is now a center point for trail heads into the Cranberry Back Country.