The Easy Rider star's husband, Stephen Eckelberry, announced her death on his Facebook page, saying, "It is with great sadness that I have to report that my wife and best friend Karen Black has just passed away, only a few minutes ago. Thank you all for all your prayers and love, they meant so much to her as they did to me."
Black was diagnosed with ampullary cancer in November 2010 and had a third of her pancreas removed. She was declared cancer-free in 2011, but in March of this year, a fundraising page was set up to help raise public donations for experimental treatment in Europe that was not covered by insurance.
On Aug. 7, just a day before she passed, Eckelberry posted an update saying that Black had become bed-bound as the cancer had spread to her spine and back and they were unable to go to Europe. But he said he had "given up predicting what is going to happen to Karen."
"You look at the scans, they tell you one thing, then you meet Karen, and what you are left with is how amazingly alive she is," he wrote. "She can't help but take life head-on and be completely engaged in the moment, always interested, always curious, always present."
Award-Winning RolesKnown for her full lips and thick, wavy hair that seemed to change color from film to film, Black often portrayed women who were quirky, troubled or threatened. Her breakthrough was as a prostitute who takes LSD with Dennis Hopper and Peter Fonda in 1969's Easy Rider, the hippie classic that helped get her the role of Rayette Dipesto, a waitress who dates – and is mistreated by – an upper-class dropout played by Jack Nicholson in 1970's Five Easy Pieces.
Cited by The New York Times as a "pathetically appealing vulgarian," Black's performance won her an Oscar nomination and Golden Globe Award. She would recall that playing Rayette really was acting: The well-read, cerebral Black, raised in a comfortable Chicago suburb, had little in common with her relatively simple-minded character.
"If you look through the eyes of Rayette, it looks nice, really beautiful, light, not heavy, not serious. A very affectionate woman who would look upon things with love, and longing," Black told Venice Magazine in 2007.
"A completely uncritical person, and in that sense, a beautiful person. When [director] Bob Rafelson called me to his office to discuss the part he said, 'Karen, I'm worried you can't play this role because you're too smart.' I said 'Bob, when you call "action," I will stop thinking,' because that's how Rayette is.'"
In 1971, Black starred with Nicholson again in Drive, He Said which Nicholson also directed. Over the next few years, she worked with such top actors and directors as Richard Benjamin (Portnoy's Complaint), Robert Redford and Mia Farrow (The Great Gatsby) and Charlton Heston (Airport 1975).
She was nominated for a Grammy Award after writing and performing songs for Nashville, in which she played a country singer in Robert Altman's 1975 ensemble epic. Black also starred as a jewel thief in Alfred Hitchcock's last movie, Family Plot, released in 1976.
"We used to read each other poems and limericks and tried to catch me on my vocabulary," she later said of Hitchcock. "He once said, 'You seem very perspicacious today, Miss Black.' I said, 'Oh, you mean "keenly perceptive?" 'Yes.' So I got him this huge, gold-embossed dictionary that said 'Diction-Harry,' at the end of the shoot."
Black was married four times. She is survived by Eckelberry, a son and a daughter.