[11] The Mongols are designated an organized crime group by the United States Department of Justice, the Australian Federal Police, and Europol.

[4][17] The Mongols' original sergeant-at-arms, Alfonso "Big Al" Aceves, served three tours of duty in Vietnam with the 101st Airborne Division.

[20] The Mongols' membership increased as the club began recruiting inmates, particularly from the California Men's Colony in San Luis Obispo.

[19] According to law enforcement, a skull and crossbones patch worn by a Mongol indicates that the member has killed on behalf of the club.

[4] Additionally, a tattoo reading "RFFN" (an acronym of "respect few, fear none") is allegedly only permitted to be worn by a Mongol who has committed an act of violence against a member of the Hells Angels.

[31] Mongols members are also known to wear Las Vegas Raiders-branded clothing in order to circumvent bans on gang colors.

[34][35] In a 2015 racketeering case in Los Angeles, the Federal government tried and failed to use civil forfeiture laws to seize all rights to the Mongols emblems and patches in order to forbid members from wearing them.

[20] The Mongols' international headquarters is located in Southern California,[46] formerly based in Montebello[11] and Commerce,[27] and currently in West Covina.

[27] According to prosecutors, the dues collected by the "mother chapter" are used to fund and promote the club and to pay for the legal expenses of members.

[44] The Mongols have an estimated membership of between 1,000 and 2,000 internationally, with chapters in 17 countries; Australia, Belgium, Brazil, Canada, England, France, Germany, Israel, Italy, Malaysia, Mexico, the Netherlands, Norway, Singapore, Sweden, Thailand and the United States.

[47][48][49] The Mongols are considered by law enforcement agencies in the United States to be among the "big five" motorcycle gangs, along with the Bandidos, the Hells Angels, the Outlaws and the Pagans.

[51][52] Mongols members have a long history in the illegal drugs trade (especially methamphetamine), money laundering, robbery, extortion, firearms violations, murder, and assault, among other crimes.

[36] On March 23, 2024, a San Bernardino County Sheriff's Deputy, Christopher Bingham, was arrested and accused of being an active member of the Mongols.

Bingham, a firearms expert and former gun shop owner, was riding with two club members and carrying an unregistered Glock 9mm handgun.