Dubuque's small role in "The Big Sleep"

It's funny how you can return to a favorite book and become surprised by little, forgotten details.
I read RAYMOND CHANDLER'S 1939 novel "THE BIG SLEEP" this week for the first time in several years, prefacing the return by reading both "KILLER IN THE RAIN," a 1935 short story that formed the basis of the indecent literature blackmail plot and "FINGER MAN," the 1936 short story that provided the basis for the Eddie Mars gambling den segment of the novel. Chandler frequently "cannibalized" his short stories for his later novels.
Having read the earlier stories provided me the opportunity to see Chandler at work, fleshing out the original plots as he folded them like ingredients into his "Big Sleep" concoction.
However, they didn't prepare me for the surprise of seeing the DUBUQUE reference in "Big Sleep."
The parents of Owen Taylor, the Sternwood's dead chauffeur, are said to be from the Key City, and Dubuque makes two appearances in print in "Big Sleep." I laughed seeing the city mentioned -- I had completely forgotten that little detail from previous readings of "Big Sleep."
I'm considering devoting most of my autumnal reading to HARD-BOILED FICTION.
I doubt if Dubuque will show up again within the pages, but I'm prepared to be surprised.