Margot Kidder, who starred as Lois Lane in the "Superman" film franchise of the late 1970s and early 1980s, has died.

Franzen-Davis Funeral Home in Livingston, Montana, posted a notice on its website saying Kidder died Sunday at her home there. She was 69.

No further details were given and messages left with Kidder's representatives were not immediately returned.

"Superman" was a superhero blockbuster two decades before comic book movies became the norm at the top of the box office.

Both Kidder and co-star Christopher Reeve, who played Superman, were relative unknowns when they got their leading parts, and neither saw many major roles afterward. Reeve died in 2004.

Kidder was close to her "Superman" co-star, saying, "When you're strapped to someone hanging from the ceiling for months and months, you get pretty darned close." When Reeve died, Kidder said, "I can't stop thinking about Christopher because he was such a huge part of my life. He was just such a great guy. …He was complicated, very smart, really smart, and he knew he'd done something meaningful. He was very aware of that and very happy with that role."

The actress was rocked by struggles with bipolar disorder in the 1990s and had a breakdown in 1996, which led to a brief stint with homelessness. She spoke candidly about her experience afterward and advocated for destigmatizing mental health issues.

The actress was married three times. Her last marriage was to actor John Heard, which ended in divorce in 1980. Kidder is survived by daughter Maggie McGuane.  

The Canadian-born Kidder also appeared in 1975's "The Great Waldo Pepper" with Robert Redford and 1978's "The Amityville Horror."

(The Associated Press, CBS News contributed to this report.)