Sue Morgan gets Hoppy and his friends to join their expedition looking for Indian artifacts. Expedition leader Atwood makes a deal with nearby cattle rustler Morgan to loot the Indian treasures instead and sell them. Hoppy is on to their plan and pretending to leave follows them. Not only is he outnumbered by Morgan's men, but California has himself about to be sacrificed in an Indian ritual.

• Hopalong Cassidy Productions Inc.
• William Boyd
• Andy Clyde
• Rand Brooks
• Fritz Leiber
• Douglas Evans
• Harry Cording
• Betty Alexander
• Francis McDonald