Harvey met his second wife, Josepine Morong Runnels (née Whistum Analyx or Whist-am-nallyx), during a concert in an opera house owned by her father.

Josephine, a member of the Sanpoil Native American tribe in the Pacific Northwest and granddaughter of chief Que Que Tas, was in the midst of a divorce from her husband George Whitely.

He joined the Spade Cooley Band performed with the Sons of the Pioneers and eventually made it to Hollywood where he was one of the busiest bit part players in B-Westerns of the late 1930s.

Gahan began his 1935-1942 screen career as a member of several hillbilly music groups, including being an original member of the band known as The Arizona Wranglers (aka The Range Riders), which also included stalwart B-Western player Jack Kirk, stuntman Jack Jones, and actor Deuce Spriggins.

He wrote many well-loved cowboy songs and sold them to better known performers such as Bob Nolan, Roy Rogers, and Gene Autry.