Maine State Prison
The Maine State Prison was erected in Thomaston, Maine in 1824 and relocated to Warren in 2002. This maximum-security prison has a capacity of 916 adult male inmates with an average daily population of 900.

History
In 1824, only four years after Maine broke off from Massachusetts and became its own state, the state legislature established the Maine State Prison in Thomaston (). The original layout of the prison "had underground cells—deep holes into which prisoners were lowered each night and brought up in the daytime to labor in the stone quarry on the prison property". In 1923 the prison was destroyed by a fire in which many inmates died. The old prison was replaced by a facility with two cellblocks. The cells were modeled on the Auburn System. There were long narrow hallways with very small cells— each. The 1923 prison was very modern for the time and most things were performed by technology, like the locking and unlocking of doors.

The Maine State Prison had a farm several miles away where select prisoners worked. Most produce was used by the prison and not for sale. Other prisoners worked in carriage shops, harness shops, and in maintenance. In the summer of 1927 there were 197 white prisoners, three African American prisoners, and one prisoner of another race. The Maine state prison housed few females, who worked sewing and patching clothing. The women were relocated to the Women's Correctional Center in Skowhegan, Maine in 1935.

New location
The old Maine State Prison in Thomaston was moved to a new, larger prison in Warren in February 2002 because of the growing prisoner population. Some residents in Thomaston objected to the relocation of the prison out of their town, because it was a part of their history and local economy. The prison that was founded 178 years ago was razed in the summer of 2002. The site of the prison in Thomaston is now a field.

Incidents
 In 1998, Michael Chasse was arrested for breaking into the home of Robert Cohen, the brother of former Maine Senator William Cohen. As Chasse was being escorted to his trial for the break-in, he threw a white powdery substance into the guards’ faces and ran off, but was caught five hours later.  
 On November 11, 2005, Portland Phoenix newspaper began an exposé series detailing the prison's alleged misuse of forcible extraction techniques and restraint chairs. Following a wave of public criticism, Corrections Commissioner Warren Magnusson promised to "de-escalate" use of the restraint chair, and asked the US Department of Justice's National Institute of Corrections to review the management of Maine Supermax.
 On June 30, 2008, Chasse, by then a prisoner of the Maine State Prison, took another prisoner and a staff member hostage. Chasse had what appeared to be a knife taped to his hand. After a seven-hour stand off, the two hostages were released with minor cuts. On November 3, 2011 Michael Chasse died while at the New Jersey State Prison, where he had been sent since Maine could no longer hold him in the prison due to his behavior.
 Gary Watland, a prisoner at the Maine State Prison serving a 25-year sentence for murder, devised a plan to have his wife, Susan Watland, bring a gun into the prison with the intent of taking hostages. Another prisoner alerted staff. On October 24, 2006 Susan Watland entered the prison with a loaded pistol but was apprehended by officials before any shots were fired. She was arrested and later sentenced to 3 years in prison with credit for time served, probation, and a fine. She has since been released. Gary Watland has since been transferred to the Federal Supermax Prison, ADX Florence.

Special Management Unit
The Special Management Unit (SMU) is a restrictive housing unit that houses prisoners who are threats to themselves or others, are escape risks, or violate institutional rules, such as fighting or having weapons or other contraband, or are in need of protection. Most prisoners in the SMU are on 23-hour lockdown. They receive one hour a day exercise in a recreation yard and most services, such as meals and medication, are brought to them in their cells. Prisoners who behave in such a way as to constitute a danger to themselves or others can be restrained with force, including use of chemical restraints (mace), placed in security smock/bedding, and put on a constant observation status until mental health staff determines that the prisoner is safe. If extremely agitated, they can be placed for short periods of time in a restraint chair only until they regain control of their behavior and are assessed by mental health staff.

Prison management
The Maine State prison is the only prison in Maine that can legally use the unit management system. A team of staff for each housing unit meets periodically to talk about the needs of each prisoner, determine their custody level, and set goals for each prisoner to reach. Education programs are available to inmates including GED prep, typing, English, horticulture, science, and college prep math.  College courses are also available for prisoners. Prisoners placed in the SMU have access to educational, mental health, and other programs in-cell.