1. August 1950: A 24-year-old Marilyn, wearing a simple button-down shirt monogrammed with her initials, leans against a tree in Los Angeles' Griffith Park for LIFE photographer Ed Clark. The negatives for these photos were recently discovered during our ongoing effort to digitize LIFE's immense and storied photo archive, including outtakes and entire shoots that never saw the light of day
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2. Lounging in the shade, Monroe studies lines of an unknown script. It was still early in her career, and she'd just begun to grab attention: Three months before this shoot, she appeared as a crooked lawyer's girlfriend in "The Asphalt Jungle," and two months after, she had a small role as an aspiring starlet in "All About Eve."
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3. A barefoot Monroe balances on rocks over a tiny brook. In a 1999 interview with Digital Journalist, photographer Clark described how in 1950 he received a call from a friend at 20th Century Fox about "a hot tomato" the studio had just signed: Marilyn
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4. Marilyn turns to the camera. "She was unknown then, so I was able to spend a lot of time shooting her," photographer Clark recalled in the 1999 interview. "We'd go out to Griffith Park and she'd read poetry. I sent several rolls to LIFE in New York, but they wired back, 'Who the hell is Marilyn Monroe?' Later, though, they did a cover of my shot of Marilyn and Jane Russell in 'Gentlemen Prefer Blondes.'
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5. Monroe, changed into a bikini top, relaxes with a script. Why LIFE never published this gold mine of photos after Marilyn became a superstar remains a mystery. The only clue: a brief note about the shoot we found in our archives, addressed to LIFE's photo editor and saying that "this take was over-developed and poorly printed
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6. Marilyn flashes a brilliant smile. It's hard to believe that just four years earlier, she was Norma Jeane Dougherty, the wife of a Merchant Marine and a worker in a munitions factory
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7. Monroe appears to be acting out a scene. At the time, she was under the instruction of legendary acting coach Natasha Lytess
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8. Marilyn gets her feet wet. Though it looks like a beautiful day here, the note LIFE found in its archives about this shoot reads, "The weather has been poor, which has held up our outdoor shooting on her."
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9. Marilyn, in Dappled Sunlight.
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10. Monroe, beautifully framed by the foliage. She was discovered in 1946, after 20th Century Fox exec Ben Lyon noticed the modeling Marilyn on magazine covers and arranged a screen test for her. "It's Jean Harlow all over again," he is reported to have said.
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11. Today, of course, Monroe is remembered as the ultimate sex symbol -- but Ed Clark's camera captures something else here: a not-yet-packaged young woman unaware of what lies in store for her.
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12. Marilyn pats her curls. Naturally a brunette, Monroe reportedly dyed her hair blonde during her modeling days, after hearing that's the look agencies wanted.
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13. Monroe leans over a railing, her short-shorts riding up. Four years later, she'd famously show off those legs again during the subway-grate scene of "The Seven Year Itch.
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14. A glimpse of the future superstar as she walks -- in adorable saddle shoes -- down a trail. (Want more Marilyn? Follow her life, her loves, and her career in photos.)
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15. In 1953, three years after the Griffith Park shoot, Ed Clark visited the set of "Gentlemen Prefer Blondes," where he captured many of the iconic moments from the film. Here, Marilyn performs "Diamonds Are a Girl's Best Friend," the number that later inspired Madonna's "Material Girl" video. See more photos of Marilyn Monroe on the set. (And if you're interested in even more Marilyn, pre-order LIFE's "Remembering Marilyn" book.)
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16. Clad in a show-stopping red velvet dress and fur stole, 25-year-old starlet Marilyn Monroe glides across the floor of the Club Del Mar in Santa Monica, Calif., in January 1952. At this party, the actress — who'd just enjoyed another tiny but scene-stealing part in the comedy As Young as You Feel — would receive one of her very first career awards: the "Henrietta" for Best Young Box Office Personality, given by the Foreign Press Association of Hollywood
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