Wabash Valley Correctional Facility is a prison situated south of Terre Haute, located in Haddon Township, Sullivan County, just north of Carlisle, Indiana.

The SNU is a mental health treatment unit designed to house Seriously Mentally Ill offenders who have been designated as needing intensive mental health treatment and programming within the Indiana Department of Correction.

Offender participants may be transferred into the unit from any other facility in the state.

When participants arrive, they are assessed and placed in the program's phase system.

Phase four offenders additionally go outside of the unit for special programs and meals.