Goofs

In a fight scene between Otis Kaylor and one of the 3 loggers, Otis Kaylor gets pushed onto the floor and does a somersault. Whilst doing this somersault, his hat falls off. Otis Kaylor quickly then gets up and his opponent swings a wooden stick at his face. At this point Otis Kaylor's hat reappearing on his head.

Harry Truman, contrary to his depiction in the movie, never owned a dog. In fact, at the time of the eruption he owned 16 cats and raccoons all of whom lived indoors with Truman.

The first "newscast" in the movie mentions the Iran Hostage Crisis as being one of the major news-makers of the day. It however erroneously states several figures. The movie states that there were 53 hostages, yet only that many were held to the end. In that newscast, the anchor also says, "Today marked the 129th day of captivity for the 53 American Hostages..." On March 20, 1980, when activity began, that would have actually put the real duration for the hostage crisis at 106 days.

On the morning of May 18, about two hours before the eruption, Clyde Whitaker is shown berating a logger for showing up to work late. May 18, 1980 was a Sunday; all logging companies were closed (this is why the body count was not much higher than it was).

David's Ford pickup truck has Chevrolet hub caps on it.

When Harry Truman plays the piano, he is clearly faking the movements (his hands don't come close to matching the music).

When the helicopter is losing control, there is a close up shot of the altimeter rapidly unwinding. You can see a hand winding the adjustment knob in the corner of the screen.

There was no highway anywhere near Mount St. Helens numbered "607" as mentioned during a brief scene at the Mount St. Helens Lodge. There was, however, a major access road that led to Spirit Lake, called State Route 504.