Margot Kidder, Lois Lane Of 'Superman' Films, Dead At 69

LOS ANGELES (CBSLA) — Margot Kidder, the actress best known for playing Lois Lane in the "Superman" movies of the late 1970s and early 1980s, died Sunday. She was 69.

Kidder passed away at her home in Livingston, Montana, according to a funeral home listing.

The actress-turned-activist became a champion for mental health following her Hollywood career after battling bipolar disorder.

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.

GALLERY: Celebrity Deaths 2018

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

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

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)