The San Fierro Triads are large gangs originating from Hong Kong, who have since moved to San Fierro. There are three Triad factions in San Fierro consisting of a set hierarchy with small sets answering to larger sets; the Blood Feather Triad, which would later be slaughtered by the Da Nang Boys, the Red Gecko Tong led by Ran Fa Li, and the Mountain Cloud Boys. The most prominent gang in the group, the Mountain Cloud Boys, is operated by the blind Wu Zi Mu and answers to the Red Gecko Tong.
The sets of the SF Triads are heavily involved in joint operations and avoid violent conflict between the Triad factions, with the Mountain Cloud Boys establishing an alliance with the Red Gecko Tong. The SF Triads are also allied with the Grove Street Families, and are rivals with the Mafia, the Da Nang Boys, and the Loco Syndicate.
In addition to their bases of operations in San Fierro, the SF Triads also own and operate a casino hotel venture called The Four Dragons on the Las Venturas Strip; ownership shared between Wu Zi Mu, Ran Fa Li and protagonist Carl Johnson. Because of intense Mafia pressure in the city, the Chinese Triads attempted to flex their muscles to show the Mafia that they can hold their own on The Strip. While the SF Triad's prime business is gambling, Wu Zi Mu has shown motivations towards robbery and street racing.
Carl Johnson, having been exiled from Los Santos after the fall of the Grove Street Families, works for Wu Zi Mu's faction and helps them to destroy the Loco Syndicate and neutralize the Da Nang Boys (the Triads, on the other hand, seem to be on neutral relations with San Fierro's other gang, the San Fierro Rifa). In return the Triads aid Carl in robbing Caligula's Palace, give him a share in The Four Dragons Casino, and help him in seizing Madd Dogg's mansion back from a drug dealer so the Grove Street Families could spearhead their return. The mansion serves as CJ's own base of operation in his return to Los Santos.
SF Triad members don all-black suits or all-grey suits. While the Triad gang members appear on the streets in Chinatown, Calton Heights and northern King's, San Fierro, they do not appear on Las Venturas streets, even areas surrounding the Four Dragons Casino, although they can be seen on several cutscenes and missions.