The Park County Coroner's office is conducting the investigation into the cause of death, but foul play is not considered a factor. It's surely what got her the role.
Canadian-born Kidder appeared in more than 70 movies and TV shows, including "The Great Waldo Pepper", "The Amityville Horror" and the 2014 children's TV series "R.L. Stine's The Haunting Hour", for which she won an Emmy award.
Margot Kidder also made headlines for her battle with bipolar disorder, and she was briefly homeless in the mid-1990s during a manic episode. Police later responded to a call about a woman hiding behind a home, and Kidder was later identified and described as "dirty, frightened and paranoid", according to the Independent. She was 69 years old.
She told ABC's Barbara Walters in a 1996 interview that she had struggled for decades with mental illness, a fight that became public when she was found dazed and filthy in a yard not far from the studio where she once played Lane. But she had continued to act on television, in film and occasionally onstage. During her life, she was married three times, including to the late actor John Heard in 1979... for six days.
Kidder is survived by her daughter, Maggie McGuane, from her first marriage to American novelist Thomas McGuane.