Dennis Hopper, 74, the rogue actor and director who kick-started a new era of indie moviemaking with his trippy '60s road picture,

Easy Rider

, who turned a nitrous-sucking villain in

Blue Velvet

into an icon of roaring weirdness, and who worked in the great American movie genres with any number of great American moviemakers, died Saturday in Venice, Calif. He had been diagnosed with advanced prostate cancer last fall.

Mr. Hopper, who was also a painter, a sculptor (as a child, he took art classes from Thomas Hart Benton), an art collector, and an accomplished photographer, made his screen debut alongside James Dean in 1955's Rebel Without a Cause. The next year, he again worked with Dean in Giant, the Texas-sized family saga that also starred Rock Hudson and Elizabeth Taylor. In the late '50s and early '60s, Mr. Hopper worked in westerns, war movies, and thrillers, on the big screen and on television - an intense presence with a rebellious glare, lurking on the sideline as bigger names, and bigger talents, perhaps, carried the show.

But in 1969, Mr. Hopper's journeyman career became something else when he teamed up with Peter Fonda and Jack Nicholson to shoot and star in - for a meager $400,000 - the counterculture biker movie Easy Rider. Hopper is Billy, Fonda is Wyatt, and the two hippie drug-dealer dudes let their motors run through the Southwest, riling the locals, and meeting the inspired nut ball George Hanson (Nicholson) along the way. Released in the summer of Woodstock, the film, codirected by Mr. Hopper and Fonda (with legendary disputes), captured the cultural turmoil of the day: the antiwar movement, the sexual revolution, the drugs, the music.

Easy Rider earned almost $20 million in its initial release, a success that shook the old studio system to its core, and helped usher in a new generation of actors, writers, and filmmakers.

As a director, Mr. Hopper never again came close to that kind of artistic or commercial success, but Out of the Blue (1980), with Linda Manz as a girl trying to cope with the messed-up grown-ups in her life (including Hopper, as her father), and The Hot Spot (1990), a sun-burnished neo-noir with Don Johnson, Jennifer Connelly, and Virginia Madsen, have much to recommend.

Mr. Hopper's excesses in life - drugs, drink, divorce, rehab, and then drugs, drink, divorce, and rehab, again - often seemed to bleed into his work on screen. He is the stoned-out photojournalist in Francis Ford Coppola's Apocalypse Now (1979); he's a boozehound on welfare in Coppola's Rumble Fish (1983); and he's Frank Booth, the sex-fiend sociopath of David Lynch's 1986 American surrealist gem, Blue Velvet.

Reportedly, after reading Lynch's script, Mr. Hopper called the director and said, "You have to let me play Frank Booth. Because I am Frank Booth!"

People had little trouble believing that.

That same year, Mr. Hopper appeared in the haunting youth drama River's Edge (as a killer) and in Hoosiers, in the role of a basketball-obsessed drunk - a performance that gained him a supporting actor Academy Award nomination. His career was on the rebound - again. He was the mystery man in the cool Western noir Red Rock West (1993). He was the villain in the Keanu Reeves-Sandra Bullock smash Speed (1994), and he was the angry (and eye-patched) antagonist in the postapocalyptic Kevin Costner flop, Waterworld (1995).

Mr. Hopper worked steadily over the last two decades. He appeared as himself on HBO's Entourage, he was a pitchman for Nike, Ford, and the Gap, and he had a starring role in the 2008-09 TV series Crash.

Born in Dodge City, Kan., and reared in Kansas City, Mo., Mr. Hopper moved to Southern California with his family when he was a teen. He started acting in high school and pretty much never stopped, embracing the Method - and embracing a bit of madness that served him well in a career full of crazed villains and unhinged souls.

Mr. Hopper was married and divorced five times. His first marriage was to Brooke Hayward, daughter of actress Margaret Sullavan and producer Leland Hayward. His second was to Michelle Phillips, the model and Mamas and Papas singer. That one lasted a week.

His fifth, to Victoria Duffy, ended only this January: Mr. Hopper, extremely ill, filed for divorce, charging that his wife had walked off with prized pieces from his collection of contemporary art. Over the years, Mr. Hopper had acquired and then sold works by such luminaries as Warhol, Lichtenstein, and Basquiat.

Mr. Hopper is survived by four children, and by a filmography of close to 200 titles.