When Coogan (Clint Eastwood) is searching the New York City nightclub, the large screen plays a scene from Tarantula (1955), a "B" science fiction movie which was Eastwood's fourth movie.
The helipad shown in the movie closed in 1968, the release date for the movie. However, it reopened in 1973, but closed permanently following a helicopter roll-over crash which killed several people on the roof top and a woman on the street below.
This movie was the inspiration for the television series McCloud (1970) starring Dennis Weaver. Herman Miller had written the story for this movie and then later changed a few details to create McCloud.
According to screenwriter Dean Riesner, who held script meetings after-hours with Clint Eastwood in his hotel, "I'd leave his suite, and I'd be going down the hall, and there'd be some girl coming down the hall from the opposite direction and heading into Clint's room." Added Riesner, "There were always a bunch of girls around him, I'll tell you that. Gals from the office, gals around the set, gals in the picture."
Coogan's Bluff in New York City is the name of a large cliff extending northward from 155th Street in Manhattan, near the film's climax in Fort Tryon Park in Washington Heights. From 1890 to 1964 it overlooked the fabled Polo Grounds, home of baseball's New York Giants, and the first home of the New York Mets before the Polo Grounds was demolished in 1964.