Factual error: In Chapter 68, Trashcan Man finds a BAR (Browning Automatic Rifle) in a guard booth outside a nuclear storage facility in mid 1990. The BAR was phased out of US military service in the mid 1950's.
Continuity mistake: In Ch. 72, Stu describes finding Harold dead, and recalls that "Harold still clutched the Permacover notebook in one stiffening hand." But earlier, in Ch. 64, Stephen King states that Harold "put the Permacover notebook into the Triumph's saddlebag" immediately before shooting himself.
Continuity mistake: In chapter 47 Stu, Harold, Glen and Frannie rescue a group of women from the 4 rapists. Originally he says the 9 of them walked to a farmhouse to spend the night. The following day it's stated the 4 women joined their party when it should say 5.
Continuity mistake: Chapter 8, it says on June 18, 5 hours after talking to his cousin Hap, Joe Bob blah blah blah... But on June 18th, Hap is already in Atlanta, as they were picked up on the 17th per the previous chapter. Then he does in to say that Harry Trent stopped in a dinner in East Texas and when he came out gave directions to a new Yorker going back home (I'd think they vacationed in California) but then he says the kids loved Disney world in Orlando.
Other mistake: In Chapter 59, Stu says that Nick "might have had his hands right on the shoebox", when the bomb inside went off. But Stu had no way of knowing that the bomb was hidden in a shoebox, he ran out of the house before it was even discovered. The only one who got close enough to see it was Nick, who was killed in the explosion.
Character mistake: In Chapter 62, Dayna Jurgens is talking to Randall Flagg. Flagg states that he has no intention of going to war, saying that "If humanity continues, let our grandfathers fight it out". He even repeats it; "Or their grandfathers". What Flagg must mean to say, is that their grandCHILDREN could fight it out.