Counties referred to like cities

[Rothman]

It seems like it's fairly common to refer to most of Nevada's counties without "County", since there's only 17 of them. (I guess you can't do it with Elko County because Elko city exists.) During the election, you'd see Nevada-based commentators referring to "the mail returns from Washoe", "early voting in Clark", "I didn't know they even had the Internet in Esmeralda", and things like that.

New York does that. It's Nassau, Suffolk, Rockland, Westchester, and Putnam.  Other counties like Orange County are called that as well as Duchess and Ulster are followed by county.

It's inconsistent in New York with this usage.

That might be a downstate thing.  If the "definition of upstate vs. downstate" thread were still active, I'd even list that as a possible criteria.

I don't know.  I have a friend from Rockland County that switches back and forth himself when talking about the county.