The Nancy Drew books are set in the town of River Heights, which in the 1930 edition of The Secret of the Old Clock was described as being in the Midwest. In subsequent books, however, River Heights seems to be located in the East, only a few hours' drive from New York City.

The lack of change in River Heights gives the books an essentially timeless quality. Nancy encounters modern problems such as the escape of refugees from Warsaw Pact countries, but enemy spies seem no more sinister than the local thieves of earlier books. In fact, Adams revised the entire series in 1959, removing language that might make the books dated or offensive.