Michael Blake, a struggling writer whose novel “Dances With Wolves” became a hit movie in 1990 and earned him an Academy Award for the screenplay, died May 2 in Tucson, Ariz. He was 69.

The cause was cancer, said his business partner, Daniel Ostroff.

Mr. Blake, the author of several novels, is best known for “Dances With Wolves,” which he wrote while broke at the urging of a longtime friend, the actor Kevin Costner.

The novel, a Civil War epic about Army lieutenant who befriends a Native American tribe, was fairly unsuccessful when it came out in 1988.

Costner asked Mr. Blake to adapt it into a movie. The book went on to sell 3.5 million copies after the film version, which starred and was directed by Costner.

“Dances With Wolves” won seven Academy Awards, including best picture and director and one for Mr. Blake for best adapted screenplay.

The film was known for its comparatively sensitive treatment of Indians in an industry that often presented them as villains.

“I was interested in knowing more about the Indians from the time I was a little boy,” Mr. Blake once told the Detroit Free Press. “I picked up every book I could find, and every one broke my heart. Among all the Indian groups, there was a spirituality that was transcendent and a way of life that was marvelous. ‘Dances with Wolves’ is about my devastation to think that way of life is gone and we had no chance to learn from it.”

Mr. Blake advocated for many causes, including literacy, Native American history and the disappearing of wild horses in the West, said his wife, Marianne Mortensen Blake.

He was born Michael Lennox Webb on July 5, 1945, at Fort Bragg, N.C., where his father was in the Army; he legally changed his surname to his mother’s maiden name.

He lived with his family in Texas before settling in southern California. He served in the Air Force from 1964 to 1968 and briefly attended the University of New Mexico.

He took film classes at the University of California at Berkeley in the 1970s, and a classmate named Jim Wilson became a movie producer.

In 1983, Mr. Blake wrote the screenplay for “Stacy’s Knights,” a gambling drama that starred Costner and was produced by Wilson. For the next few years, nothing came of his follow-up efforts to write for Hollywood. For a time he was living in his car and on friends’ couches before Costner surged him to adapt “Dances With Wolves” for the screen.

Besides his wife, survivors include three children and a brother.

— from staff and news services