Trip with the Teacher (1975)

Directed by Earl Barton
My rating: 3 stars out of 4
IMDb
(DVD, BCI Eclipse)

A group of teenage girls and their teacher take a school bus into the desert on a field trip. The bus breaks down, but they are helped by some bikers. Instead of bringing them to the nearest gas station they take them to an abandoned shack where they are tormented and raped. Zalman King is the sicko biker and he plays the part to the hilt. He is one of the creepiest screen villains I've seen in quite some time, reminding me of Dennis Hopper in Blue Velvet. The girls eventually get some help from a "good biker" and the bad guys meet violent deaths. This one is a sleeper in the exploitation genre and much better than its reputation.