When I bought my Upstate weekend cottage in 2005, I was a complete real estate neophyte. I saw this one house, asked few questions, and didn't attend the home inspection. I told my sister excitedly that I was buying a place in The Catskills in a town called Claryville, and she asked if that was anywhere near Denning, a beautiful place she'd visited a couple of times for a friend's annual weekend gathering at their historic family demesne. My answer was that it didn't ring a bell.
Claryville is in Denning, as it turns out. So for all of you who scratch your heads when you see two "towns" listed for each property, here's the skinny: What you and I would call towns are technically "hamlets", or as the MLS lists them, "cities", which we know is certainly a misnomer up here. Hamlets are grouped together for the purposes of shared government, so that rather than every pokey place having their own town hall, government and their functions like highway department (road maintenance), taxing authority, zoning and that type of thing are covered by one umbrella body. Those entities are referred to as "towns", as in the Town of Denning. There are 15 towns in Sullivan County and 20 towns in Ulster County.
Town/County tax bills go out every January, and reflect rates required to cover the budget of that town (or grouping of "hamlets") plus contributions to the county budget. So when looking at real estate listings, the overall rate of taxation by town may be quite relevant. In Sullivan County the Town of Neversink has the lowest taxes because of a deal they reached with the City of New York when the Neversink Reservoir was created (by flooding Neversink) to provide drinking water to the city. The Town of Fallsburg has the highest.
But as with all rules, there are some confusing aspects. Some hamlets have parts in different towns. Taking Claryville, for example, part of it is in the Town of Neversink, and the other in the Town of Denning. Callicoon, a pretty "hamlet" (it's actually a terrific town/business district) along the Delaware River, is NOT in the Town of Callicoon; it's in the Town of Delaware. And Callicoon Center is a separate hamlet altogether, but IS in the Town of Callicoon. Go figure.
And while we're on the subject, school districts are separate from distinct town boundaries. In fact, schools may incorporate several towns and cross over town or even county lines. So the school district, which has its own taxing authority (school tax bills go out every September), can play a large part in the amount of taxes attached to a property.
Hope that goes some way to demystifying some of the labeling you see regularly on real estate listings.