Factual error: Elvis and Ann Margaret take a trip in a helicopter over Hoover Dam and Lake Meade. They are flying in a small 2 seater copter with a bubble canopy and no doors. During the trip Elvis and Ann talk to each other without headphones or microphones in a normal tone of voice. In that type of helicopter, especially one with no doors, the sound would have been deafening and they wouldn't have heard each other even while screaming.
Viva Las Vegas (1964)
1 factual error
Directed by: George Sidney
Starring: Ann-Margret, Elvis Presley, William Demarest, Cesare Danova
Continuity mistake: Ann Margaret is seen dancing with high heeled shoes at the beginning of a dance routine and during the routine is seen in flat ballet shoes, then near the end she is seen wearing high heeled shoes again.
Man in garage: That's quite a rig, I never saw anything like it.
Lucky Jackson: Yeah, it's one of a kind, I built it myself.
Trivia: It was during the filming that Elvis first heard of The Beatles when someone had their first English LP on the set. He took it into his room and listened to it for hours. He then banned their music from the set.