Usage question: “back of” - period or regional variation?

This is a question of usage or syntax, depending upon how you look at it. I’ve been reading a lot of fiction written in the 40s and 50s - it’s wonderful for building a sense of how people talked in the period I’m writing about, and of quotidian details of life that are hard to get from histories.

I’ve repeatedly encountered a usage of the phrase “back of” that isn’t part of my own speech, and I wonder whether it’s a usage that has faded with time, or a regional variation, or something else. I see it frequently enough that I know it isn’t one author’s quirk. Here’s one example, from Vera Caspary’s Laura (1942):

“...walking quickly alone down that deserted street to the garage back of Andrew Frost’s house...”

In my idiolect - I was born in the early 70s and grew up in New York City - I would say “the garage in back of Andrew Frost’s house” or “the garage behind Andrew Frost’s house.”

Is this usage part of your regular speech? If so, if you don’t mind, where are you from, and how old are you?

I often use Google Ngrams to chase down questions of period usage, but in this case many of the “back of” hits are really “the back of” and other irrelevant usages. My 1991 OED describes it as a chiefly US usage, which is pretty interesting, but doesn’t really answer my question.

Thanks for all the comments!

Bufty said:

We would use ...in the back of my mind, put something in the back of the cupboard, get back in line, come back here.....etc., etc....

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These are all very different usages from the sense I'm talking about, though. None of these is analagous to "behind Andrew Frost's garage," which is the sense of "back of" that struck me unusual. Unless what you're saying is that it also strikes you as unusual.

blacbird said:

I've both heard it and read it, fairly often. A slight variation would be "in back of", used likewise. It's informal, but far from uncommon. And it presents no confusion to a reader.

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What you call "a slight variation" is, as I said in my first post, the difference between a usage that is in my idiolect and one that is not. "In back of" used to mean "behind" is entirely familiar to me. "Back of" used to mean "behind" is unusual to me. That slight variation is exactly what I'm asking about.

It sounds like some of you are familiar with the usage, which makes sense, as I see it in enough books of the 40s-50s to know it was in wide use. It's an interesting variation that caught my ear -- too subtle to use as a way to add period flavor to my writing (it would either just sound completely normal, or (as it does to me) would sound notable, but not in a way that would be strongly associated with the period), but still really interesting.