The Hells Angels were formed on March 17, 1948, by the Bishop family World War II veterans in San Bernardino, California followed by an amalgamation of former members from different motorcycle clubs, such as the Pissed Off Bastards of Bloomington. The Hells Angels' website denies the suggestion that any misfit or malcontent troops are connected with the motorcycle club. The website also notes that the name was suggested by Arvid Olsen, an associate of the founders, who had served in the Flying Tigers' "Hell's Angels" squadron in China during World War II. The name "Hell's Angels" was inspired by the typical naming of American squadrons, or other fighting groups, with a fierce, death-defying title in World Wars I and II, e.g., the Flying Tigers (American Volunteer Group) in Burma and China fielded three squadrons of P-40s and the third Squadron was called "Hell's Angels". In 1930, the Howard Hughes film Hell's Angels displayed extraordinary and dangerous feats of aviation, and it is believed that the World War II groups who used that name based it on the film.
Some of the early history of the HAMC is not clear, and accounts differ. According to Ralph "Sonny" Barger, founder of the Oakland charter, early charters of the club were founded in San Francisco, Gardena, Fontana, Oakland and elsewhere, with the members usually being unaware that there were other clubs. One of the lesser known clubs existed in North Chino/South Pomona, in the late 1960s.
Other sources claim that the Hells Angels in San Francisco were organized in 1953 by Rocky Graves, a Hells Angel member from San Bernardino ("Berdoo") implying that the "Frisco" Hells Angels were very much aware of their forebears. The "Frisco" Hells Angels were reorganized in 1955 with thirteen charter members, Frank Sadilek serving as President, and using the smaller, original logo. The Oakland charter, at the time headed by Barger, used a larger version of the "Death's Head" patch nicknamed the "Barger Larger", which was first used in 1959. It later became the club standard.
The Hells Angels are often depicted in semi-mythical romantic fashion like the 19th-century James–Younger Gang: free-spirited, iconic, bound by brotherhood and loyalty. At other times, such as in the 1966 Roger Corman film The Wild Angels, they are depicted as violent and nihilistic, little more than a violent criminal gang and a scourge on society.
The club became prominent within, and established its notoriety as part of the 1960s counterculture movement in San Francisco's Haight-Ashbury scene, playing a part at many of the movement's seminal events. Members were directly connected to many of the counterculture's primary leaders, such as Ken Kesey and the Merry Pranksters, Allen Ginsberg, Jerry Garcia and the Grateful Dead, Timothy Leary, The Beatles, The Rolling Stones, Mick Farren and Tom Wolfe. Writing a book about the club launched the career of "Gonzo" journalist Hunter S. Thompson.
In 1973, members from several branches of the organization protested at an Environmental Protection Agency hearing about a proposed transportation plan that included restrictions on motorcycle use and sales to get California to meet the new Clean Air Act standards.