

Sureño gangs use the number 13, which represents the thirteenth letter of the alphabet 'M,' to show allegiance to the Mexican Mafia. Most Sureño gangs in Southern California feud with each other on the streets but members are required to set aside conflicts when they enter the prison system.

Examples include: Vicky's Town (Stockton & San Jose), Varrio Mojado Sureño (Stockton & Lodi ),Angelino Heights (Santa Rosa & Sacramento), East Side Clanton (San Jose), La Primera (Petaluma & Rhernat Park), Brown Brotherhood (Vallejo), Little Town Rifa (Bay Point, West Pittsburg & Antioch), PlayBoys Sureños (Stockton & Lodi) 18th Street (Eureka & San Rafael) & MS.13 (San Francisco & Concord). Sureño gangs in northern California are referred to as "Upstate Sureños." Some upstate Sureño gangs were established by relocated gang members from Southern California. Maravilla gangs from East Los Angeles do not identify as Sureño but they are still aligned with the Mexican Mafia. All present day gangs in southern California and some in northern California aligned themselves with the Mexican Mafia. Most northern California Chicano gangs aligned with the Nuestra Familia and were designated as Norteños. Chicano street gangs started aligning themselves with either the Mexican Mafia or the Nuestra Familia.

The Sureño designation for southern California Chicano street gangs was established in the 1980s as a result of the continued conflict between the Mexican Mafia and Nuestra Familia prison gangs. Continued list of Sureño gangs that pay tribute to the Mexican Mafia.
