Mystery Mountain is a 1934 American Western serial film directed by Otto Brower and B. Reeves Eason and starring Ken Maynard, Verna Hillie, Syd Saylor, Edward Earle, and Hooper Atchley.

[1] Distributed by Mascot Pictures, Mystery Mountain features the second ever film appearance by Gene Autry.

Her railroad worker father (Lafe McKee) was the first victim of the murderous fiend known as the Rattler, who is especially difficult to catch because he makes himself appear as other people with a collection of masks, or he effects a strange disguise with eyeglasses, a fake nose, and a crepe-hair mustache.

[1] According to the book The Great Movie Serials: Their Sound and Fury, Ken Maynard was doubled by Cliff Lyons in some scenes but performed many of his own stunts, especially riding, in others.

The physical similarities between the two makes it difficult to spot the difference on screen between actor and stuntman.