There are (I think) six maps in Psycho. Three are just part of the establishing decor. The first (above), in the office in Phoenix (it is probably a map of Phoenix), draws far less attention than the two large landscapes to the right of it.
The second, in the office of the used car lot in Gorman, may not even be a map at all:
The third, in the corridor outside the office of the Chief of Police, in Fairvale, is no doubt supposed to represent that locale, but the map has no identifiable features:
The other three maps are more interesting. One is on the front page of the ‘Los Angeles Tribune’ which Marion buys in Gorman:
Though the lines of the map are distinct, I cannot identify the locale: possibly it relates to the headline concerning the establishment of a new water district in Los Angeles (though it appears to represent an eastern coastline). Since, anyway, the newspaper is a fictional construct, its headline and illustrations can have been assembled from very disparate sources. Our gaze is constantly returning to this map, not for its topographical interest but because Marion wraps the money in it.
The next map is a globe, a familiar type (see the previous entry in this listing), and is here in a familiar setting, as an item in the bric-à-brac of Norman’s room. It signifies only the minimum that globes can signify when attention is not drawn to them by the film (merely pointing to a world beyond the film's locales):
The last map is the most interesting. In the Police Chief’s office, the psychiatrist offers his explanation of Norman’s behaviour. He speaks for five minutes, and for almost all of that time he is standing in front of a map on the wall. There are occasional cuts away for questions and reactions from his audience, but mostly we are looking at the psychiatrist and a map:
In The Moment of Psycho (2009), David Thomson identifies this as a map of Shasta County, northern California,and demonstrates that this is a feasible location for the town in which the film’s action comes to a close. Psycho has moved from Phoenix, a real place rendered with a panoramic view and identified in screentext:
to ‘Fairvale’, a fiction confected on the studio lot. Though the map is not easily decipherable, it is peculiar that the film here undermines earlier efforts to detach the town from topographical reality, though perhaps only Shasta County residents would have recognised the place on the map from this closer detail:
Detachment from exact reality is the dominant note here. The film had began with chronological exactitude on Friday December 11th (1959):
carrying over to the murder of Marion on Saturday the 12th. Arbogast’s investigation then stretches vaguely over the following week, until he is murdered on Saturday the 19th. Things come to a head on the Sunday, and the closing scene at the county courthouse seems to take place that evening. No dates are specified, but a calendar in the office reads ‘17’:
meaning either that the Police Chief's calendar has not been changed since the preceding Thursday, or that the film is no longer concerned with being exact ('It's tough keeping track of the time', had said Norman).
This would harmonise with the view (presented by David Thomson) that the ‘psychological explanation’ is itself at some remove from exact reality -- that Hitchcock was ‘pulling our leg’.