Here is some information about Rockland County which may help those of you living elsewhere who need to do research in Rockland County.
Rockland County was part of Orange County until 1798. When the first US census was done in 1790, there were only two towns in what became Rockland County - Haverstraw and Orangetown. By 1800, brand new Rockland County consisted of four towns: Clarkstown, Haverstraw, Hempstead (which later became Ramapo) and Orangetown. This census is available here. Clarkstown and Hempstead had separated from Haverstraw in 1791. Stony Point didn't separate from Haverstraw until 1865.
Now Rockland County consists of five towns:, Clarkstown, Haverstraw, Orangetown, Ramapo, and Stony Point. While there are villages called "Haverstraw" and "Stony Point" which appear on maps, Clarkstown, for example, will not appear as a dot on a map.
Within each of the five towns there are villages. If you have the name of a village your ancestor lived in, it will be helpful to know the town that village is part of when searching records.
These are the towns and the villages therein:
Clarkstown: Bardonia, Central Nyack, Congers, Nanuet, New City, Rockland Lake, Upper Nyack, Valley Cottage, West Nyack and portions of the Villages of Nyack and Spring Valley
Haverstraw: Haverstraw, part of Pomona, Garnerville, Thiells, Mt. Ivy, West Haverstraw
Orangetown: Blauvelt, Grandview-on-Hudson, Nyack, Orangeburg, Palisades, Pearl River, Piermont, South Nyack, Snedens Landing, Sparkill, Tappan
Ramapo: Airmont, Chestnut Ridge, Hillburn, Kaser, Monsey, Montebello, New Hempstead, New Square, part of Pomona, Sloatsburg, Spring Valley, Suffern, Tallman, Viola, Wesley Hills
Stony Point: Grassy Point, Jones Point, Stony Point, Tomkins Cove
Other information is available at the County of Rockland site (click here). Click on County Clerk in the list at the left, then go to Archives to see what is available.
There's an excellent list of the churches in Rockland, with the dates they were in existence, at the Rockland Genealogical Society site (Click Here). Be sure and scroll all the way to the bottom and check out the references.