Prelude to the brawl Īt the Flamingo Hilton casino, a group of Mongols stormed in to stare at the Hells Angels. The Hells Angels stayed at the Flamingo Hilton while the Mongols stayed at Harrah's. On 25 April 2002, Sonny Barger, the Hells Angel leader arrived in Laughlin for the River Run. 5 Hells Angels chapters in southern California. In 2002, the Mongols had 39 chapters in southern California vs. The Mongols had been expanding in southern California. The Mongols tended to be younger and many did not know how to ride motorcycles while the Hells Angels tended to be middle-aged and usually did know to ride motorcycles. The Mongols were 90% Hispanic while the Hells Angels were all white. The Mongols were the only outlaw biker gang allowed to wear California on their patches after winning a biker war with the Hells Angels over the issue in the 1970s-1980s, which caused much ill-will. Amongst the bikers who arrived in Laughlin were the members of the Hells Angels and Mongols.
Every April about 100, 000 people arrive in Laughlin for the River Run. Laughlin is a town just 80 miles south of Las Vegas that in 2002 had 9 casinos and 8, 000 people.
The River Run riot was a violent confrontation between the Hells Angels and Mongols motorcycle clubs that occurred on April 27, 2002, in Laughlin, Nevada during the Laughlin River Run.