People reports that the actress passed away at her home in Livingston, Montana on Sunday. No cause of death was given.
Kidder had had a prolific acting career long before she starred alongside Christopher Reeve in 1978's "Superman: The Movie," getting her start in the 1960s and working steadily throughout the ensuing years. But it was her turn opposite the Man of Steel that skyrocketed her into stardom, and she appeared in three additional films as Lois Lane: 1980's "Superman II," 1983's "Superman III," and 1987's "Superman IV."
In addition to those super flicks, Kidder starred in movies including "The Amityville Horror," "Black Christmas," "Heartaches," "The Gravy Train," "Shoot the Sun Down," and "Some Kind of Hero." She also worked in television in later years, including series such as "Shell Game," "Captain Planet and the Planeteers," and "Boston Common."
Kidder struggled with mental illness throughout her life, and made headlines in 1996 after a bizarre string of episodes. Reported missing by her family, the actress was discovered days later in Los Angeles, convinced that she was being followed. She was taken to a local medical facility for observation, and later told People that she had been diagnosed with manic depression years earlier.
Kidder is survived by her daughter, Maggie McGuane.