Links to county websites in the Mid-Hudson Valley:

Columbia County Website: http://www.columbiacountyny.com/
Columbia County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=10/

Delaware County Webiste: http://www.co.delaware.ny.us/
Delaware County COMIT GIS Mapping: http://www.giswebhost.org/delaware/
Delaware County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=12/

Dutchess County Website: http://www.dutchessny.gov/
Dutchess County Clerk (Deeds on-line): http://www.co.dutchess.ny.us/CountyGov/Departments/CountyClerk/
Dutchess County Parcel Access: https://gis.dutchessny.gov/parcelaccess/parcelaccess_map.htm
Dutchess County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=13/

Greene County Website: http://www.greenegovernment.com/
Greene County Image-Mate: http://greene.sdgnys.com/index.aspx
Greene County GIS WebMap: http://gis.greenegovernment.com/giswebmap/
Greene County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=19/

Orange County Government Website: https://www.orangecountygov.com/27/Government
Orange County Deeds Online (Paid subscription required): https://searchiqs.com/nyora/
Orange County Image-Mate: http://http://propertydata.orangecountygov.com/search.aspx
Orange County GIS (New site; in progress): http://gis.orangecountygov.com/orangecounty/
Orange County GIS (Old site; requires Adobe Flash): http://ocgis.orangecountygov.com/
Orange County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=33/

Putnam County Website: http://www.putnamcountyny.com/
Putnam County Deeds Online (paid subscription required): https://www.searchiqs.com/NYPUT/Login.aspx
Putnam County eParcel: http://www.putnamcountyny.com/itgis/eparcel/
Putham County Image-Mate: http://putnam.sdgnys.com/search.aspx
Putnam County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=37/

Rockland County Website: http://rocklandgov.com/
Rockland County Clerk (Deeds on-line): http://www.rocklandcountyclerk.com/
Rockland County GIS Portal: https://geopower.jws.com/rockland/
Rockland County Interactive Base Map (Tax maps, Planimetric, etc): https://geopower.jws.com/rockland/apps/Base/index.html?config=config.xml/
Rockland County Preliminary FEMA Flood Maps: https://geopower.jws.com/rockland/apps/MuniMap/index.html?config=config_ABFE.xml/
Rockland County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=39/

Sullivan County Website: https://www.sullivanny.us/
Sullivan County Deeds Online (Paid subscription required): https://searchiqs.com/nysul/
Sullivan County Image-Mate: http://webapps.scgnet.us/IMO/disclaimer.aspx
Sullivan County Open Data GIS Mapping: https://gis2017-04-13t155717567z-sullconygiso.opendata.arcgis.com/
Sullivan County Address Mapping App: https://sullconygiso.maps.arcgis.com/apps/webappviewer/index.html?id=0b732302d61e47e6a03a52998bd62a2f
Sullivan County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=48/

Ulster County Website: http://www.co.ulster.ny.us/
Ulster County Deeds Online (Paid subscription required): https://www.searchiqs.com/NYULS/Login/
Ulster County Image-Mate: http://gis.co.ulster.ny.us/SDGimo/disclaimer.aspx
Ulster County Parcel Viewer: http://gis.co.ulster.ny.us/
Ulster County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=51/

Westchester County Website: http://www3.westchestergov.com/
Westchester County Parcel Viewer: http://giswww.westchestergov.com/wcgis/Mapping.htm#Municipal_Tax_Parcel_Viewer
Westchester County Assessment Roll Dates: http://orpts.tax.ny.gov/cfapps/MuniPro/muni_theme/county/00fiscal.cfm?swis=55/