Theodore Olsen was born in Rhinelander, Wisconsin. He graduated from Rhinelander High School in 1950 and from Stevens Point State College (now the University of Wisconsin at Stevens Point) in 1955. Originally, he had planned on being a comic strip artist but eventually found his passion in writing rather than in art. In 1955, after many rewrites, he sold his first book, Valley of the Hunted to Ace Books. It was published in 1956 as Haven of the Hunted. Olsen has written other genres besides westerns, including adventure, gothic, romance and historical. He has written under various pen names as well, such as Christopher Storm, Cass Willoughby, and Joshua Stark. His novel The Stalking Moon was made into a movie The Stalking Moon (1968) and his novel Arrow in the Sun became the movie Soldier Blue (1970) in 1970. He died of a stroke on July 13, 1993 at his home in Rhinelander at the age of 61.