Watching “Mulholland Dr.” recently, I was reminded that Diane Selwyn/Betty Elms repeatedly says that she’s from “Deep River, Ontario”. This is usually chalked up as an allusion to the dream-nature of the film, or to Lynch’s fondness for the phrase. (In “Blue Velvet”, Dorothy Vallens lives at the “Deep River Apartments”.)
It seems worth noting, however, that Deep River, Ontario is not only a real place, it’s a pretty unusual one. It was originally a secret city built, as part of the Manhattan Project, to house the scientists and technicians working at the Chalk River Laboratories. If nothing else, this casts a different light on Diane/Betty’s probable family background.