Gridley is mining silver from an old Mexican mine and bringing it into the USA thru a passage into his worthless mine. Border guard Rogers suspects Gridley and finally finds the secret entrance to the Mexican mine. He sends Lee Madison for help only to have her captured by Gridley. Trigger brings help that takes care of Gridley's men and now Roy has to rescue Madison.
Roy Rogers
as Roy Rogers
Trigger
as Trigger
Dale Evans
as Lee Madison
Andy Devine
as Cookie Bullfincher
John McGuire
as Rex Gridley
Olaf Hytten
as Lionel Bates
David Sharpe
as Henchman Ulrich
Fritz Leiber
as Padre
Hank Patterson
as Deaf bus passenger
Fred 'Snowflake' Toones
as The Cook
Eddie Acuff
as Bus Driver
Bob Nolan
as Bob
