In the scene at the dock, watchful viewers will notice the stern of the U.S. Coast Guard Cutter 'Alert' as the camera pans toward Russ and Zadok. The Alert just happened to be docked where the scene was shot, and the cinematographer lined up the shot so the name of the boat was visible, but no one noticed until editing that the name of the cutter was the same as the ship in H.P. Lovecraft's story 'The Call of Cthulhu'.
Screenwriter/executive producer Grant Cogswell sold his house and everything he owned to help finance 'Cthulhu'.
On the crew's last day shooting in Astoria, a storm began which took out all the power in the city for several hours, and ruined three of the film's locations: the windows were blown out of the net shed, ruining thousands of dollars worth of materials stored within: the house where Tori Spelling's character Susan lives was partially destroyed by the fall of the hundred-year-old tree in the driveway (visible in the film); and the entire cul-de-sac on which Julia's house stands came down the hill in a mudslide.
The first news clippings handled by Russell (Beloved garbageman ...) features HP Lovecraft biographical details (interest in literature) as well as a reference to the Necronomicon and Abdul Al Azred, while the second (Children ...) is an actual short biography of Lovecraft and quotes HPL's name.
Both articles have a title which does not relate to the text.
In the dock scene, when Zadok is gesticulating at the rail, he actually knocked the Object into the 40-foot-deep Columbia River! This one-of-a-kind piece had to be retrieved by divers for shooting the following morning.