Suffered a fatal heart attack while watching a performance of the Broadway play "The Squall" at the old 48th St. Theater with her mother. The performance came to a halt when Mathis suddenly screamed out, "Oh, mother, I'm dying." She was carried out to the theater alley, where she was pronounced dead.
Did not actually edit Erich von Stroheim's masterpiece Greed (1924) from ten hours to 2-1/2. She was instructed by Metro to cut the film and left a memo about the matter to a regular editor, Joseph Farnham, who did the actual cutting. Mathis had worked with Stroheim before and admired the themes in his work.
One of the highest paid executives in Hollywood while she was alive.
Discovered Rudolph Valentino.
Was a Spiritualist.
Enjoyed writing comedies though she is more known for her dramatic films.
Was voted the third most important woman in Hollywood by AMPAS in 1926. Only Mary Pickford and Norma Talmadge outranked her.
In 2009 the first in-depth biography on June Mathis was published by Hala Pickford in "Rudolph Valentino: A Wife's Memories of an Icon".