1967 - Mount Massive Asylum for the Criminally Insane is established. Three scientists are murdered by an unknown patient. Authorities order the asylum to cease all activities.
1971 - Mount Massive Asylum is finally closed.
2009 - The clinic was re-opened by the Murkoff Corporation, which for the next several years conducts illegal experiments on patients with the sole purpose of gaining profit.
October 4, 2012 - An anonymous employee, later revealed to be Michelle Haas, files a complaint to Murkoff's Human Resources regarding patient and staff's safety issues at the asylum. Over the course of next few days, The Pauls, the company's litigation officers, discover that Richard Trager had sexually assaulted Michelle and attempted to cover it up. The incident resulted in Haas being given a severance package for her silence and Trager transferred down to the Underground Lab to be used as one of the Morphogenic Engine's test subjects.
September 17/18 - The Walrider escapes and starts wreaking havoc, indirectly inciting the fatal incident. A few hours later, investigative journalist Miles Upshur arrives to the asylum after receiving an anonymous tip about Murkoff's illegal activities.
1950s - 1960s
Photos of former personnel (1950-60's) still hang in the Asylum.
- Clyde Perry Director of Historical Refinement 1959-1961
- Jermain Dallaire Deputy Director, Colonic Hydrotherapy 1968
- Olivier W. Baranczyk Assistant Director of Behavioral Medicines 1954-1963
- Silas Knisely Human Resources and Corrections 1959-1966
- Thomas Wilter Father 1966
- Wilfred Panzram Archbishop of the Denver Archdiocese 1958
- Patrick Petryna employee, awarded with Team Player Award
- Administration Block/Return to the Administration Block/Exit: The exterior and interior of the asylum consisting of an outside courtyard, an indoor lobby, several corridors containing offices, libraries, and security rooms, and a halfly flooded basement where the block's generator resides. It also contains a church.
- Prison Block/Prison: Where the violent patients are imprisoned. Contains several blocks of prison cells, is glued together by several airlocks, and has a shower room at its heart.
- Sewer: The underground sewer system of the asylum.
- Male Ward: A large system of wards where the male patients are treated. It also contains a cafeteria, laundry room, and a bathing room.
- Courtyard: A courtyard arena where several maintenance sheds are housed.
- Female Ward: A large system of wards where the female patients are treated. It is suggested this is one of the oldest, if not the oldest, building in the asylum as female patients have been absent for some time and the entire building is extremely old and decaying.
- Underground Lab: A brightly lit underground complex of offices, laboratories and security rooms dedicated to powering the complex's heart: the Morphogenic Engine. Can be accessed by either several hangers that lead to outside or an elevator near the Administration Block's church. It is located 122 feet below the asylum's surface.
- Hospital: Resembling a more modern combination of both aforementioned wards, the Hospital is a large network of laboratories, patient rooms, and plastic-wrapped corridors where the patients undergo the Morphogenic Program.
- Recreation Area: A fenced-in courtyard where the patients are given fresh air and a few moments of recreation, including basketball.
- Drying Ground: Another outside courtyard where several guard posts and towers are stationed.
- Vocational Block: A large block containing an old above-ground attic/storage room looking even older than the Female Ward. The Vocational Block has several arts-and-crafts tools housed in it, implying that this building was made to keep the patients busy with artistic tasks like sewing.
- Mount Massive is based off a real mountain of the same name, located in the Sawatch Range of the U.S. state of Colorado.
- Mount Massive Asylum is modeled after H. H. Richardson Complex, which is also a mental asylum located in Buffalo, New York.