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 their rivals, the Da Nang Boys; the Red Gecko Tong, which is led by Ran Fa Li; and the Mountain Cloud Boys (山雲男孩). 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 Triads are heavily involved in joint operations. The Mountain Cloud Boys establish an alliance with the Red Gecko Tong. The SF Triads are also allied with the Grove Street Families, and are having problems with the Mafia (Leone Family, Forelli Family, Sindacco Family), and are enemies with the Da Nang Boys.
In addition to their bases of operations in San Fierro, the Triads also own and operate a casino hotel venture called The Four Dragons Casino on the southern tip of The Strip in Las Venturas; ownership is shared between Wu Zi Mu, Ran Fa Li and Carl Johnson. Because of intense Mafia pressure in the city, the Triads attempted to flex their muscles to show the Mafia that they can hold their own casino on The Strip. While the Triad's prime business is gambling, Wu Zi Mu has shown motivations towards robbery and street racingCarl 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 destroy the Loco Syndicate and neutralize the Da Nang Boys. 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 Vagos 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.
Triad members don all-black suits or all-grey suits. While the Triad gang members appear on the streets in Chinatown and Calton Heights in San Fierro. Strangely, 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. They usually wield AK-47s and pistols, however in certain missions they can be seen with different guns.
Much like Varrios Los Aztecas will react generally friendly to CJ but will react hostile to him if provoked.