From Jesse James and Butch Cassidy to Scarface and Tony Soprano, outlaws have always held a singularly ambiguous place in America’s popular imagination: we fear and loathe gangsters’ appetite for violence; we envy and covet their freedom.

In early 1965, LIFE photographer Bill Ray and writer Joe Bride spent several weeks with a gang that, to this day, serves as a living, brawling embodiment of our schizoid relationship with the rebel: the Hells Angels.

Here, in a gallery of remarkable photographs that were shot for LIFE but never ran in the magazine, Ray and Bride recall their days and nights spent with Buzzard, Hambone, Big D, and other Angels (as well as their equally tough “old ladies”) at a time when the roar of Harleys and the sight of long-haired bikers was still new and — for the average, law-abiding citizen — close to unfathomable. The day-to-day existence of these menacing, leather-clad creatures, after all, was as foreign to most of LIFE magazine’s millions of readers as the lives of, say, headhunters in Borneo, or nomads of the Gobi Desert.