It was established in 1977, but according to Jimmy Santiago Baca’s book called “A Place to Stand” it may have been earlier. The book describes the author's run in with the Mexican Mafia in the prison of Florence, Arizona.

This is part of the same faction of the Mexican Mafia that was formed in the California prison system in the late 1950's. From my knowledge, I know that the "Godfather" of the Arizona Old Mexican Mafia was 2nd in Command to the Godfather from California. J.J. and Snake were the two guys who led this faction in Florence Arizona, and were set to be transferred to Marion, Illinois for some brain implant surgery.

In 1984 a split occurred and a second gang, known as "Arizona's New Mexican Mafia" emerged. A fierce rivalry developed between them and the Old Mexican Mafia. Old Mexican Mafia members are subject to attack by the New Mexican Mafia members if they are placed in the prison population together

The Old Mexican Mafia patterns itself after the organizational structure of the California Mexican Mafia, which includes as its leaders a General, Captains, Lieutenants, and soldiers.

Common Tattoos - "Two blocked M’s with a skull and bat wings above"

Prison Criminal Activity - Narcotics, Extortion, Assaults, Homicides and Gambling

Specific Tattoo/Symbolism: Will usually be two M’s. Sometimes a skull with wings protruding from both sides of the skull located above the two M’s. And/or the words “Mexican Mafia” or “EME”

Trends: Courting alliances with the Border Bros., Grandel, and Southside Posse. It still has an alliance with California-Federal EME (Source: Arizona Department of Corrections Web Site, Jimmy Santiago Baca’s “A place to stand” and other informant sources.)