Hi,

I don't think you'll find death certificates for this time frame. Birth, marriage and deaths were recorded at the city/town/village Town Clerk on cards (kinda like index cards).

1820 Hampstead, Rockland, New York
Jno Gurnee

1830 Ramapo, Rockland, New York
Abigail Gurnee

You can do a Google search for Ramapo New York Town Clerk.

Do a Google search on Mount Ivy Cemetery Pomona New York and you might be able to find an inventory of who is buried there.

If they're not there, you can do a Google search for Rockland County New York Cemeteries and look for them in the inventoried cemeteries. Successful Searching!