The Hells Angels bike gang has had a rough 2011 in California.Three Northern California members have died violently amid a turf battle with a rival bike gang. Law enforcement officials of the motorcycle club's home state are pursuing and jailing members, with 26 Angels and their associates arrested in San Diego.The violence spilled into public view in the unlikeliest of places when thousands of Harley-Davidsons rolled up to a San Jose cemetery to bury a Hells Angels leader who was gunned down earlier in 2011 at a Nevada casino.LOYAL TO THE DEATHA Hells Angel allegedly shot and killed a fellow member at the cemetery and fled - the latest sign of the in-fighting and violence that has plagued the gang in recent months. If the deadly gunfire was not enough, a member was plowed down by a van a week later an alleged victim of road rage.While no one is predicting the demise of the notorious outlaw motorcycle club, law enforcement officials and gang experts said the Hells Angels' recent woes still stand out for an organization they describe as violent, sophisticated and disciplined with loyal-to-the-death members.Jay Dobyns, an agent with Bureau of Alcohol, Tobacco, Firearms and Explosives, infiltrated the Hells Angels in Arizona for two years beginning in 2001. Dobyns says that: "They are the heavyweight champions of the biker gang culture. And every other biker gang wants the belt."FOUNDED IN 1948The organization has a long history in California, dating to its founding in 1948 by returning Second World War veterans in the dusty town of Fontana and including a notorious incident during a Rolling Stones show in Altamont in 1969 in which a spectator was stabbed by a Hells Angel working security. A jury later acquitted the killer, finding he acted in self-defence.The US Department of Justice says the Hells Angels now have as many as 2500 members in 230 chapters in 26 countries and are a major source of drug-trafficking.Authorities have pursued the club for decades, infiltrating it with undercover agents, prosecuting suspects with harsh charges once reserved for the Mafia and indicting members on charges ranging from drug trafficking to mortgage fraud.Yet the club continues to flourish.They have opened chapters worldwide, aggressively enforced their trademarks in court like a responsible Wall Street corporation and won high-profile acquittals and other legal battles with law enforcement.GANG VIOLENCEThe ATF, which handles many biker cases, said it arrested more outlaw motorcycle gang members in 2010 than any other since 2003. Police in Germany and Canada also report a surge in motorcycle gang violence, with much of it connected to the Hells Angels.The California Hells Angels' current problems are partly rooted in a battle with the Vagos, a California-based motorcycle club founded in the 1960s. The clubs have been bitter enemies dating at least back a decade to a violent 2001 confrontation at a Costa Mesa swap meet.Kent Shaw, the California Attorney General's acting head of law enforcement, says: "These groups are trying to expand their membership and dominance. "There's going to be a number of clashes and it seems to have gotten worse over the last couple years. It seems to be coming to a flash point," said Shaw.After dozens of Vagos took over a bar in Lakeport, California, and rode their motorcycles up and down the main drag, officials went so far as to close the downtown to traffic on May 14.Lake County Sheriff Frank Rivero said the Vagos were making a statement about controlling the region after one of its members was allegedly beaten by Hells Angels earlier in the year. Rivero put up a road block that day after the California Highway Patrol and FBI warned that Hells Angels were traveling toward town.'BASIC RESPONSE'The Angels turned back before reaching the road block. Now the district attorney is investigating whether the sheriff violated the club members' civil rights with his plans to stop them. The sheriff is unapologetic.Rivero said: "It's a basic response. I'm not going to tolerate gang violence in Lake County."A month later, a Vagos member and a friend were severely beaten in a casino. Four Hells Angels have been charged with assault. Three were arrested and the sheriff said they were bailed out by fellow Angel Steve Tausan, who owned a bail bonds company. A fourth is being sought.In September 2011, the two gangs fought again.San Jose Angels leader Jeffrey Pettigrew was slain during a wild shootout with rival Vagos in a Reno-area casino in September.More violence occurred at Pettigrew's burial. Two shots were fired, and Tausan, Pettigrew's friend and high-ranking Angel, lay bleeding with a mortal wound. Police suspect fellow Angel Steve Ruiz of firing on Tausan after they argued over the casino shooting and whether enough was done to protect Pettigrew, the president of the San Jose chapter.Police are now searching for Ruiz, who reportedly was hustled into a waiting car, leaving behind his motorcycle. Investigators initially feared Ruiz was killed and went so far as to dig up Pettigrew's grave in search of a body. But now police believe he is on the run with his girlfriend.San Jose police were out in force Saturday as Tausan was laid to rest at the same cemetery where he was killed during the October 15 funeral. A police spokesman said there were no reports of any disturbances or violence.FIERCE RIVALRYThe Hells Angels didn't respond to numerous phone calls and email messages sent to their clubhouses in San Jose and Santa Cruz, where Tausan served as the chapter's sergeant at arms.The Angels have always maintained they are a club of motorcycle enthusiasts who are unfairly regarded as an organized crime syndicate because of the crimes of a few members acting independently. The club participates in charity events, such as "Toys for Tots" motorcycle runs and blood drives.The club's Web site states: "When we do right, nobody remembers. When we do wrong, nobody forgets."Karen Snell, a lawyer who won a $1.8 million settlement in 2005 after the San Jose chapter filed a lawsuit claiming illegal police searches during a murder investigation, said Pettigrew, Tausan and the others involved with the case were serious businessmen with families.Snell said: "They were really responsible clients. In my all my interactions with them, they were always gentlemen."Both Pettigrew and Tausan are dead.Karen Tausan, Steve's sister, said: "We lost our brother, our father, our son and our friend. He left a big hole in our family and we can only hope this will come to an end now."