The Mayans Motorcycle Club controls northern California and all of Nevada beside Las Vegas. The President of their Oakland chapter is Marcus Alvarez and all of their members seem to be Hispanic, most likely Mexican. They run two heroin factories near Oakland and are also involved in prostitution. Their insignia is a Mayan tribal symbol and they are based on the real-life Mongols MC. Their cuts bare the phrase "Los Asesinos de Dios" which in English means Assassins of God.
At the beginning of Season One, they stole the Sons of Anarchy's guns from their weapon storage and burned down the warehouse, prompting a turf war over the right to rule the San Joaquin Valley. They planned to use these guns to hijack a One-Niners heroin shipment. However, the Sons of Anarchy located the guns in an industrial storage warehouse, called Marcalva, in San Leandro and retaliated by stealing the guns back and destroying the building, as well as killing three Mayans members in the process. The Mayans then allied themselves with the Nordics in an attempt to break the Sons of Anarchy's iron-fisted control over the town of Charming, as the SOA supply their competition with weapons. They also provided muscle for the Nords' drug pushing in exchange for 20% of the profit. The affiliation was ended, however, when they tried to kill Nord leader Ernest Darby. The Mayans and SOA eventually made a deal in order to stop a war; every SOA-Mayan dispute club-wide would end in the Sons' favor, and the SOA will begin selling the Mayans weapons. However, when both gangs met in Oakland to make a deal, the One-Niners attacked and killed a number of Mayans.
In Season 2, the Mayans aligned themselves with the League of American Nationalists, receiving weapons that were originally meant for SAMCRO and using them to push in on One-Niner and Chinese turf. Marcus Álvarez has used his new strength to declare war on all members of the Sons of Anarchy everywhere. Later on in Season 2, the Mayans become involved with Ethan Zobelle and L.O.A.N. Initially, Zobelle provides guns to the Mayans free of charge. Later, Zobelle partners up with the Mayans to get in on the Mayans' prison heroin trade, the Mayams protect Zobelle from SAMCRO.
In Season 3, the Mayans MC owns Calavares MC and forces them to provide extra muscle during drug shipments and to perform a drive-by during the wake of slain SOA member Half-Sack. Alvarez, promised to patch-over the Calaveras.