Her death was confirmed by the Madera County, California, Sheriff's Department.
On the official "Star Trek" website, startrek.com
, Whitney was described as "one of 'Star Trek's' greatest cautionary tales and also one of the franchise's most satisfying renaissance stories." She was written out of the show in its first season and struggled with alcohol and drug problems before finding recovery, reprising the Rand role in the "Star Trek" films and devoting her life to helping others.
Originally a singer and dancer from the Detroit area, Whitney worked on Broadway and had a number of small roles in movies and TV series, including "The Real McCoys," "Hawaiian Eye" and "77 Sunset Strip," before being cast as Rand for "Trek's" debut season in 1966. The character was essentially an assistant to William Shatner's Capt. James T. Kirk.
But she struggled, telling a British tabloid she'd gotten hooked on diet pills trying to stay thin. She also had problems with alcohol, though she told startrek.com that her drinking was not that serious while doing the show.
She lasted just eight episodes on "Trek" before being let go.
Her forced departure started a spiral that took years to overcome.
"I just about killed myself over that reject. And when I would go on interviews, I would smell of alcohol. I was very Lindsay Lohan-ish, very Charlie Sheen. I was lost. I was lost and I began to bottom out," she told startrek.com in 2011. "It took me about 10 years after getting written out to come to my senses when I bottomed out."
She eventually got help while on Los Angeles' Skid Row, getting into a 12-step program. It turned her life around. (Among her supporters: Leonard Nimoy, "Trek's" Spock, who had his own battles with alcohol
"Star Trek" creator Gene Roddenberry put her in the movies, just going into production, and she appeared in "Star Trek: The Motion Picture," as well as the third, fourth and sixth entries in the series. She later appeared on the TV series "Star Trek: Voyager." By that point, she'd been promoted to Commander Janice Rand.
But by then her focus was on helping others with substance abuse problems. She devoted more than three decades to that work, going public with her own addiction at a "Trek" convention.
"When I told the fans I was an alcoholic, they all applauded. When I told them I had given myself to a higher power, they cheered again," Whitney told The (Fresno) Bee
in 2013. "I'm in a great place because I've gone full circle."
Whitney wrote a 1998 memoir, "The Longest Trek: My Tour of the Galaxy," about her experiences.
Her family wanted her to be remembered for her outreach.
"She continued her fellowship work in Fresno and Madera County, completely dedicating her life to helping herself and others find daily sobriety and a higher power out of addiction," her son, Jonathan Dweck, told the newspaper.
And if her interview with the "Star Trek" website was any indication, she loved her life.
"Right now I take my grandchildren to school and cart them around, and I'm of maximum service to them," she said. "I also line dance one night a week and I go to the gym three days a week. So, my life is happy, joyous, free, sober and saved, and a lot of fun, too. I have a lot of fun."