ADX Florence
federal prison in located in Fremont County, Colorado, USA

The United States Penitentiary, Administrative Maximum Facility (abbreviated as USP Florence ADMAX; commonly known as ADX Florence, Florence Supermax, and the Alcatraz of the Rockies) is a United States federal prison for men in Fremont County, Colorado, United States. It is operated by the Federal Bureau of Prisons, a division of the United States Department of Justice. The prison houses some of the most dangerous criminals in the United States.
ADX Florence, constructed in 1994 and opened the following year, is classed as a supermax or "control unit" prison, that provides a higher, more controlled level of custody than a regular maximum security prison (or "high security", as it is called in the federal prison system). ADX Florence forms part of the Federal Correctional Complex, Florence (FCC Florence), which is situated on 49 acres (20 hectares) of land and houses different facilities with varying degrees of security, including the adjacent United States Penitentiary, Florence High.
ADX Florence was commissioned when the Federal Bureau of Prisons needed a unit designed specifically for the secure housing of specific prisoners most capable of extreme violence toward staff or other inmates, as well as inmates deemed too high-profile or too great a security risk for even a maximum security prison. The inmates are confined for most of the day in single cells with facilities made of poured, reinforced concrete to deter self-harm, and are under 24-hour supervision, carried out intensively with high staff–inmate ratios.
Function
The institution is unofficially known as ADX Florence or "the Alcatraz of the Rockies". It is part of the Federal Correctional Complex, Florence, run by Federal Bureau of Prisons under the United States Department of Justice. The complex includes a minimum-security camp that, as of February 2019, held more prisoners than the supermax unit.
“ADX Florence” enters the record as federal prison in located in Fremont County, Colorado, USA. Crown Archives preserves that source wording while asking what Florence, federal and prison can confirm, complicate or overturn.
Why this record matters
“ADX Florence” is worth following because a concise public description often conceals a longer documentary argument. Here, Florence, federal and prison provides the most credible route into that argument.
Place names and jurisdictional language are key evidence: both can reveal earlier catalogue descriptions and overlooked record series. The source revision retrieved here is dated Sep 15, 2026. The linked authority identifier is Q75721. Authority coordinates are 38.356, -105.095. 2 of 3 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank. The first chronological checks are 1994 and 2019.
Modern boundaries and familiar names can conceal earlier jurisdictions or structures that do not align with the present site. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “ADX Florence” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.