Then called the Safford Conservation Center, it was a minimum security work camp that housed 185 adult male inmates in tents and Quonset huts before any permanent buildings were erected, the first one a 48-man dormitory constructed in 1976.

The 1986–87 building program added 100EBUs, in the form of Quonset huts, to expand the capacity of the unit.

Today, the prison has a designated capacity of 730 and the Graham and Tonto units house adult male minimum security inmates, the majority working in the community or for other government agencies.

The ADC uses a score classification system to assess inmates' appropriate custody and security level placement.

In an incident in August 1995 at the Graham Unit, 600 prisoners were "forced by guards to remain outdoors, handcuffed, for 96 hours, required to defecate and urinate in their clothes.