County · code 36105
Sullivan CountyNew York
Sullivan County is located in New York and has its county seat in Monticello. It was created in 1809 from Ulster County.
- Founded1809
- County seatMonticello
- Named forJohn Sullivan
- Land area968 sq mi + 28 sq mi water
- Population78,624 2020 Census
- Parcels mapped67,340 checked 15 October 2026
Where it is
Sullivan on the map of New York
New York has 62 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1809 from Ulster County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Sullivan County was created on March 27, 1809, from Ulster County and was named after John Sullivan.
- 1809Sullivan County created Sullivan created from Ulster. · N.Y. Laws 1808, 32d sess., ch. 126, sec. 1/p. 495
Land and parcels
What the maps cover in Sullivan
Who publishes each layer, how good it is, and when we last checked.
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Parcels Good enough
Lot lines and tax-map numbers for 67,340 parcels from New York State Geographic Information Systems (GIS) Clearinghouse. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 25 September 2026 · checked 15 October 2026 -
Address points Official
One point per address, 61,607 in all from NYS Office of Information Technology Services (ITS), Geospatial Services / GIS Program Office (AGOL org 'ShareGIS NY', owner NYSGIS_GPO).
edited 25 September 2026 · checked 14 October 2026 -
Buildings Reference
Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026
- Official
- from the office that keeps the record
- Good enough
- a reliable statewide or national copy
- Fallback
- a guide only; check the official record
- Missing
- nothing public found yet
People and land
Sullivan by the Census
Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.
Rules and offices
Sullivan County's official site
We have found the county's site but not its offices yet; start there.
County government
- County government
The official website of Sullivan County.
See your own lot on these maps
Open Sullivan County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.
Questions
Common questions about Sullivan County
- When was Sullivan County founded?
- Sullivan County was founded in 1809, formed from Ulster County, and named after John Sullivan.
- What is the county seat of Sullivan County?
- The county seat of Sullivan County is Monticello.
- Is there an online parcel map for Sullivan County?
- Yes. New York State Geographic Information Systems (GIS) Clearinghouse publishes a parcel map of 67,340 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Sullivan County's boundary or name changed?
- Sullivan County was created in 1809 from Ulster County. The Atlas of Historical County Boundaries records no boundary change since.
- Is my lot in a flood zone?
- We do not have flood maps for Sullivan County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby