LandBrief

Jefferson County

Parcel & Property Data

49,235Total Parcels
—Avg. Market Value
787,033Total Acres

About This Data

LandBrief holds 49,235 parcel records for Jefferson County, sourced from county records. Each includes the parcel boundary, and — where the county publishes them — owner, situs address, acreage, assessed values and legal description.

Data from the Jefferson County assessor roll dated December 2023, loaded August 2026. See data sources for every county’s vintage.

Explore Jefferson County

Jefferson County by the Numbers

Median parcel size
1 acres
measured from mapped boundaries
90th-percentile parcel
31.9 acres
County land area
811,475 acres
U.S. Census measurement
Communities
42
72.8% of parcels outside any incorporated place
Out-of-state owners
9.9% of parcels
by owner mailing address

Who Owns Jefferson County?

Share of the county’s 49,235 parcels by the kind of owner on record. Classified from owner names, so the boundaries are approximate; an entity the rules cannot place counts as an individual.

Owner typeShare of parcels
Individuals86.8%
Companies & organizations7.9%
Trusts & estates4.8%
Government0.1%
Other / unclassified0.4%

The largest owner on record is Thousand Islands Land Trust with 129 parcels — see the full landowner leaderboard.

Parcel Records (~49,235 total)

per page
Parcel IDOwnerAddressCityAcreage
37.00-1-1United States of AmericaAntwerp-Sprageville RdUnincorporated32012.10
57.00-1-1United States of AmericaFort DrumUnincorporated29252.10
66.00-3-1United States of AmericaFort DrumUnincorporated16228.70
47.00-2-1United States of AmericaFort DrumUnincorporated7729.60
127.00-1-2Salmon River Timberlands LLCSE Part of WorthUnincorporated6407.50
54.00-1-6New York State People ofDog Hill RdUnincorporated4344.70
121.00-1-60.1New York State DEC28114 Loomis RdUnincorporated4014.20
125.00-1-72New York State DEC20027 Co Rte 90Unincorporated3471.25
114.00-1-20.1New York State DEC25841 NYS Rte 177Unincorporated3376.97
117.00-1-93New York State DEC8437 Pierrepont PlUnincorporated3329.29
Page 1 of 4924

Download Jefferson County parcel data

All 49,235 parcels in Jefferson County as a single file — free, no account needed. Shapefile, GeoJSON, GeoPackage, CSV and Parquet.

Get Jefferson County on FreeParcelData →

Nearby counties

Frequently Asked Questions

How many parcels are in Jefferson County?

The Jefferson County assessor roll on file records 49,235 parcels across 42 communities, with 72.8% lying outside any incorporated place.

Who owns the most land in Jefferson County?

Thousand Islands Land Trust holds 129 parcels, the most of any owner on record — the largest-landowners leaderboard ranks the top 25.

What is the typical parcel size in Jefferson County?

Measured from mapped boundaries, the median parcel is 1 acres, and nine parcels in ten are under 31.9 acres. Boundary-measured area closely tracks deeded acreage but is not the deed.

How much of Jefferson County is owned from out of state?

9.9% of parcels list an owner mailing address outside NY, per the county’s own records.

How much of Jefferson County is government-owned?

Government entities — federal, state, and local — hold 0.1% of the county’s parcels, classified from owner names on the roll.

How current is this data?

It comes from the Jefferson County assessor roll dated December 2023. Counties deliver on their own schedules; the methodology page explains how records are processed and the data sources page tracks every county’s vintage.

Browse by City (42)

49,235 parcels across 42 communities in Jefferson County.