Mercer County

Parcel & Property Data

13,211Total Parcels

—Avg. Market Value

357,653Total Acres

About This Data

LandBrief holds 13,211 parcel records for Mercer 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 Mercer County assessor roll dated July 2025, loaded August 2026. See data sources for every county’s vintage.

Explore Mercer County

Largest landownersWho holds the most land in Mercer County, by total acreage.
Largest parcelsThe biggest individual tracts in the county, ranked by size.
Out-of-state ownersWho owns Mercer County from somewhere else, and where they live.

Mercer County by the Numbers

Median parcel size: 1 acres
measured from mapped boundaries
90th-percentile parcel: 84.3 acres
County land area: 359,193 acres
U.S. Census measurement
Communities: 23
26.1% of parcels outside any incorporated place
Out-of-state owners: 8.9% of parcels
by owner mailing address

Who Owns Mercer County?

Share of the county’s 13,211 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 type	Share of parcels
Individuals	72.7%
Companies & organizations	10.6%
Trusts & estates	11.9%
Government	3.9%
Other / unclassified	0.9%

The largest owner on record is CITY OF KEITHSBURG with 179 parcels — see the full landowner leaderboard.

Parcel Records (~13,211 total)

Showper page

Parcel ID	Owner	Address	City	Acreage
161632400006	SMALLWOOD R LANE TRUSTEE	—	Unincorporated	4262.00
111119200008	HARRISON STANELY T TRUSTEE	—	Unincorporated	1306.00
010126100003	PH FARMS LLC	271 140TH AVE	New Boston	627.95
010126100003	PH FARMS LLC	271 140TH AVE	New Boston	627.95
070705200002	US GOVERNMENT	—	Unincorporated	589.50
010136100004	PH FARMS LLC	305 140TH AVE	New Boston	581.82
010136100004	PH FARMS LLC	305 140TH AVE	New Boston	581.82
030322100004	BRANDA L. FRIEDEN TRUST	1447 130TH ST	Aledo	560.00
070836100005	D V L R PROPERTIES LLC	955 BLUFF RD	New Boston	556.82
010132200001	US GOVERNMENT	—	Unincorporated	550.00

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Download Mercer County parcel data

All 13,211 parcels in Mercer County as a single file — free, no account needed. Shapefile, GeoJSON, GeoPackage, CSV and Parquet.

Get Mercer County on FreeParcelData →

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Frequently Asked Questions

How many parcels are in Mercer County?

The Mercer County assessor roll on file records 13,211 parcels across 23 communities, with 26.1% lying outside any incorporated place.

Who owns the most land in Mercer County?

CITY OF KEITHSBURG holds 179 parcels, the most of any owner on record — the largest-landowners leaderboard ranks the top 25.

What is the typical parcel size in Mercer County?

Measured from mapped boundaries, the median parcel is 1 acres, and nine parcels in ten are under 84.3 acres. Boundary-measured area closely tracks deeded acreage but is not the deed.

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

8.9% of parcels list an owner mailing address outside IL, per the county’s own records.

How much of Mercer County is government-owned?

Government entities — federal, state, and local — hold 3.9% of the county’s parcels, classified from owner names on the roll.

How current is this data?

It comes from the Mercer County assessor roll dated July 2025. Counties deliver on their own schedules; the methodology page explains how records are processed and the data sources page tracks every county’s vintage.