An interesting story on Lovecraft’s visit to Vermont, and how it led to “The Whisperer in Darkness.” My wife’s family is from Brattleboro, mentioned in the story:
http://www.timesargus.com/article/20091025/FEATURES07/910250308
I’m not surprised – Lovecraft based lots of his descriptions on existing places, some of them explicit, others not. Certainly several stories feature description of Lovecraft’s own Providence, RI. And “The Horror at Red Hook” features Red Hook, NY.
There are a couple of websites claiming that Innsmouth was based in part on Gloucester, MA and Newburyport MA, and many of the buildings are still standing. (I suspect it’s also partly based on Salem, MA). And, although Lovecraft scholar S.T. Joshi thinks it ain’t so, a lot of folks think that the Dunwich of “The Dunwich Horror” derives from Mystery Hill in Salem, New Hampshire.
I’ve also long suspected that The Blasted Heath from “The Colour Out of Space” owes a debt to the Desert of Maine.
“The Whisperer in Darkness” is set in Vermont, just after the great flood of 1927, which wiped out much of the state’s transportation infrastructure. My stepfather was seven years old at the time, and remembers his father having to go to great lengths to get his older brothers back from a trip to Burlington - a twenty-minute drive today.
I’ve always liked this story for that reason.
The flooding was widespread and quite severe, and dozens died, IIRC, including the state’s lieutenant governor, who allegedly drove drunk onto a flooded street, couldn’t get out, and drowned.
And, according to Lovecraft, large pink crustacean-type things floated downriver from the hills.
Yeah, that part he made up. 
Yes…yes…it was…made up…
… an “accursed buzzing which had no likeness to humanity despite the human words which it uttered in good English grammar and a scholarly accent.”
I have a shiny box with your name on it. Please do come and take a look at your very earliest convenience! And do bring with you all of our prior correspondence any anything at all you think relevant to this question–we shall need it all as we piece together the great puzzle before us!
Yours,
Henry Akely
I’m still surprised the letter didn’t have a postscript asking Wilmarth to slather himself in steak sauce and climb into a giant cauldron.
Maybe they’ll add it for the movie.
(They probably could have done a more appropriate voice, though)
The nasssty Wilmarth brings black our black stoneses, my precioussss . . .
P.S. - How do you like my new typewriter? Nope, nothing suspicious here.