The creature's size is inconsistent, sometimes appearing to be twice the height of a person to well over thirty feet tall. Based on the size of its hands in comparison to people it grabs, a height of sixty to seventy feet is suggested.
After Bigfoot jumps on the helicopter, he falls off, it crashes and explodes; in next scene the helicopter is out of control and crashes again.
Continuity errors: When the Sasquatch is on Mount Rushmore it is seen climbing on the left hand face. The scene changes and it is seen climbing below the face. Another shift and it is again seen to be climbing on the face. It then smashes a helicopter out of the sky and the camera pulls back to show the crash. The Sasquatch is no longer on the monument, it has disappeared.
When the giant bigfoot attacks the concert while Alice Cooper is performing, the crowd starts running away except for someone in a bigfoot costume. The person in the costume drops his concert drink, and we see him a couple of times waving both of his empty hands as the giant bigfoot approaches him. But after the giant bigfoot picks him up, the costumed bigfoot is shown holding his drink again.
In one scene when Bigfoot is chasing a man rowing an inflatable boat down the river the man alternates several times between having a visible ponytail and not having a ponytail.
(at around 1 min) Deputy Walt (Bruce Davison) of the Dead Hills police has a US Marshal badge on his fur lined hat. A deputy police officer is not a US Marshal and is not entitled to wear their emblem as part of his uniform.
Harley falls face-first off Mt Rushmore, but impossibly ends up hanging off a ledge.
Towards the end of the movie when Sheriff Alvarez lights the gas on fire beside the patrol car, it doesn't give off any smoke.
In one of the opening scenes, the radio announcer refers to the Deadwood area as being part of the "Pacific Northwest".
Mount Rushmore is depicted as being visible from Deadwood. It is over thirty miles away, and the faces carved into the mountain look towards the southeast, which is the opposite direction, meaning that even if the mountain was close enough to see, the carvings would not be visible from the town. In town, a sign points the way to Rapid City, but there are no roads that directly connect Deadwood to the other town.