There are surviving roundhouses in Utica and Rome, NY... They are both used for non-railroad purposes, and the Rome one is in pretty tough shape.
I have the plans for the Utica yard from 1940, and it shows that there were 3 roundhouses, and 4 turntables. There was one roundhouse and turntable on the NYC branch going north to the Adirondacks (This roundhouse still exists).
Utica 1940^
Utica 2012v
A lone turntable on the DL&W branch going south towards New Hartford (The pit can still somewhat be seen off Oriskany Blvd.), and the other 2 NYC roundhouses I believe are gone.
Utica 1940^
Rome 2012^
While we're on this track... If anyone wants to take a look at the blueprints, we can meet for coffee! Here's a teaser of the station trackage layout...
Utica, NY Union Station 1940^
Utica, NY Union Station 2012v
Thanks,
Mario...