The Oscar- and Emmy-winning actress was attending to one of her horses earlier this week when the animal apparently knocked her down, cracking her skull and causing a concussion.
On Saturday, the 55-year-old actress was listed in fair condition at the Kootenai Medical Center's Intensive Care Unit.
"The prognosis is excellent," her husband, Michael Pearce, told the Associated Press.
At the time of the accident, Duke was reportedly trying to apply fly spray to a two-year-old filly in a barn stall on the ranch she shares with Pearce in northern Idaho, near the town of Coeur d'Alene.
According to the police report, Pearce left Duke in the barn to administer to the horse. He heard a loud thump and a cry from his wife. He ran inside to find Duke crumpled on the floor and the beast "excited and nervous and startled but not attacking."
Duke made a mini-career out of acting in The Miracle Worker. She originated the part of Helen Keller in the Broadway version in 1959 and won an Oscar in the role in the 1962 movie version, which costarred Anne Bancroft as Keller's put-upon teacher, Annie Sullivan. (Duke was 16 at the time, making her the youngest person at that point to be Oscar'd.) Nearly two decades later, Duke won an Emmy for the 1979 TV movie version but with a twist--this time she essayed the Sullivan part.
Aside from her Miracle Worker chores, Duke is probably best known for her role as identical cousins in her mid-1960s sitcom, The Patty Duke Show. Other notable credits include the big-screen adaptation of The Valley of the Dolls and an enviable list of TV movies and miniseries, including My Sweet Charlie and Captains and Kings, both of which earned her Emmys. She also played herself in the 1990 adaptation of her autobiography, Call Me Anna. (Her birth name was Anna Marie Duke--she adopted the Patty moniker early on as budding child star.) Her trophy case also includes a brace of Golden Globes and a People's Choice Award.
Duke recently costarred in the CBS TV movie Little John with Ving Rhames and Gloria Reuben.
Offscreen, Duke served a stint as president of the Screen Actors Guild in the mid 1980s and has been an outspoken advocate for those suffering manic depression, which she was diagnosed with in the early '80s. Her second book, 1992's A Brilliant Madness: Living with Manic Depression Illness, documented her battle will the illness.
Duke also mothered a show-biz rood with ex-husband John Astin (of Addams Family fame), having two actor sons, Mackenzie (The Facts of Life) and Sean (The Lord of the Rings, Rudy, Goonies). Duke and Astin split in 1985.
She met Pearce (a former drill sergeant) while making the TV flick A Time to Triumph and they married in 1986. The couple adopted a son, Kevin, in 1989.