When was Yamhill County founded?

Yamhill County was founded in 1843.

What is the county seat of Yamhill County?

The county seat of Yamhill County is McMinnville.

Is there an online parcel map for Yamhill County?

Yes. Yamhill County, OR (Assessment & Taxation) publishes a parcel map of 43,154 parcels, rated official here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Yamhill County's boundary or name changed?

Yamhill County was created in 1843. Since then the Atlas of Historical County Boundaries records 13 later changes, chiefly involving Washington County, Tillamook County and Clackamas County. It was formerly called Yamhill District.

Is my lot in a flood zone?

We do not have flood maps for Yamhill County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 41071

Yamhill CountyOregon

Yamhill County is in Oregon and has its seat in McMinnville. The county was established on July 5, 1843, as one of four original districts created by the Provisional Legislature of Oregon Territory.

Founded1843
County seatMcMinnville
Land area716 sq mi + 2.5 sq mi water
Population107,722 2020 Census
Parcels mapped43,154 checked 15 October 2026

Open the free map Click any parcel in Yamhill County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 20 October 2026

Census outline · seat marked

History

Founded in 1843

An old deed may name a county that no longer exists, or a boundary that has since moved.

Yamhill District was renamed Yamhill County on December 22, 1845, when the Provisional Legislature reorganized Oregon Territory's administrative divisions. The county lost territory to the creation of Tillamook in 1853 and to boundary adjustments with neighboring counties over subsequent decades. Yamhill became an Oregon county on February 14, 1859, when Oregon was admitted to the Union and Oregon Territory was eliminated.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

1843
Yamhill County created Yamhill District (now Yamhill) created. Yamhill was one of four original counties created by the Provisional Legislature of Oregon Territory. 5 July 1843 · Oregon Archives, p. 26
1844
Gained territory Yamhill District (now Yamhill) gained from Tuality District (now Washington).
from Tuality Districtfrom Washington
26 June 1844 · Ore. Terr. Laws, general and local, 1843-1849, p. 87
1845
Lost territory Yamhill District (now Yamhill) lost to Tuality District (now Washington); lost to creation of Non-County Area 2, apparently in preparation for the 22 December 1845 creation of Polk. Boundary between Yamhill District and Champoeg District (now Marion) redefined to run "along the middle of the main channel of the Willamette River to the center of the Columbia River at the upper mouth of the Willamette."
to Tuality District to Washington to Polkto Champoeg Districtto Marion
19 December 1845 · Ore. Terr. Laws, general and local, 1843-1849, pp. 36-37
1845
Renamed Yamhill District renamed Yamhill County; no change in boundaries.
formerly Yamhill District
22 December 1845 · Ore. Terr. Laws, general and local, 1843-1849, p. 35
1859
Became part of Oregon Yamhill became an Oregon county when the state of Oregon was admitted to the Union and Oregon Territory was eliminated. 14 February 1859 · U.S. Stat., vol. 11, ch. 33[1859], secs. 1-2/pp. 383-384 Ore. Laws 1860, 1st reg. sess., pp. 28-30

Show all 18 changes (13 more)

1843
Yamhill County created Yamhill District (now Yamhill) created. Yamhill was one of four original counties created by the Provisional Legislature of Oregon Territory. 5 July 1843 · Oregon Archives, p. 26
1844
Gained territory Yamhill District (now Yamhill) gained from Tuality District (now Washington).
from Tuality Districtfrom Washington
26 June 1844 · Ore. Terr. Laws, general and local, 1843-1849, p. 87
1845
Lost territory Yamhill District (now Yamhill) lost to Tuality District (now Washington); lost to creation of Non-County Area 2, apparently in preparation for the 22 December 1845 creation of Polk. Boundary between Yamhill District and Champoeg District (now Marion) redefined to run "along the middle of the main channel of the Willamette River to the center of the Columbia River at the upper mouth of the Willamette."
to Tuality District to Washington to Polkto Champoeg Districtto Marion
19 December 1845 · Ore. Terr. Laws, general and local, 1843-1849, pp. 36-37
1845
Renamed Yamhill District renamed Yamhill County; no change in boundaries.
formerly Yamhill District
22 December 1845 · Ore. Terr. Laws, general and local, 1843-1849, p. 35
1846
Gained territory Yamhill gained from Clatsop and Tuality (now Washington).
from Clatsop from Tualityfrom Washington
11 December 1846 · Ore. Terr. Laws, general and local, 1843-1849, p. 7
1853
Lost territory Yamhill lost to creation of Tillamook.
to Tillamook
15 December 1853 · Ore. Terr. Special Laws, 1853, 5th reg. sess., p. 6
1853
Changed Tillamook attached to Yamhill "for judicial purposes."
Tillamook
22 December 1853 · Ore. Terr. Rev. Stat. 1853, p. 63
1854
Lost territory Yamhill lost small area to Clackamas.
to Clackamas
22 December 1854 · Ore. Terr. Special Laws 1854, 6th reg. sess., p. 29
1855
Boundary clarified Yamhill boundaries redefined; exchanged with Washington.
with Washingtonno change
30 January 1855 · Ore. Terr. Special Laws 1854, 6th reg. sess., p. 46
1856
Boundary clarified Yamhill boundaries redefined; exchanged with Washington.
with Washingtonno change
21 January 1856 · Ore. Terr. Laws 1855-1856, 7th reg. sess., pp. 40-41
1857
Exchanged territory Yamhill exchanged with Washington.
with Washington
22 January 1857 · Ore. Terr. Laws 1856-1857, 8th reg. sess., p. 15
1859
Became part of Oregon Yamhill became an Oregon county when the state of Oregon was admitted to the Union and Oregon Territory was eliminated. 14 February 1859 · U.S. Stat., vol. 11, ch. 33[1859], secs. 1-2/pp. 383-384 Ore. Laws 1860, 1st reg. sess., pp. 28-30
1860
Lost territory Yamhill lost to Clackamas.
to Clackamas
17 October 1860 · Ore. Laws 1860, 1st reg. sess., p. 47
1870
Changed Tillamook attached to Yamhill "for judicial purposes."
Tillamook
22 October 1870 · Ore. Laws 1870, 6th reg. sess., pp. 24-25
1887
Exchanged territory Yamhill exchanged with Tillamook.
with Tillamook
15 February 1887 · Ore. Laws 1887, gen., 14th reg. sess., p. 147
1893
Exchanged territory Yamhill exchanged with Washington.
with Washington
22 February 1893 · Ore. Laws 1893, gen., 17th reg. sess., pp. 161-162
1981
Boundary clarified Yamhill boundary with Marion redefined to run along middle of the main channel of the Willamette River as it was located on 22 June 1981 (no change).
with Marionno change
22 June 1981 · Ore. Laws 1981, 61st reg. sess., ch. 214/p. 225
1981
Boundary clarified Yamhill redefined to amend description in Oregon Revised Statutes (no change).
no change
13 July 1981 · Ore. Laws 1981, 61st reg. sess., ch. 332/p. 356

Land and parcels

What the maps cover in Yamhill

Who publishes each layer, how good it is, and when we last checked.

Parcels Official

Lot lines and tax-map numbers for 43,154 parcels from Yamhill County, OR (Assessment & Taxation). Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 28 September 2026 · checked 15 October 2026
Address points Official

One point per address, 39,763 in all from State of Oregon — Department of Administrative Services Geospatial Enterprise Office (GEOHub) with Oregon Department of Emergency Management 9-1-1 program.
edited 16 January 2026 · checked 13 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

Yamhill by the Census

Population

107,722 2020 Census count

Housing units

40,123 2020 Census count

Land area

716 square miles

Water area

2.5 square miles

People per sq mi

150 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Yamhill 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 Yamhill County.
co.yamhill.or.us

See your own lot on these maps

Open Yamhill 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.

Open the free map no sign-in Pro early access

Questions

Common questions about Yamhill County

When was Yamhill County founded?: Yamhill County was founded in 1843.
What is the county seat of Yamhill County?: The county seat of Yamhill County is McMinnville.
Is there an online parcel map for Yamhill County?: Yes. Yamhill County, OR (Assessment & Taxation) publishes a parcel map of 43,154 parcels, rated official here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Yamhill County's boundary or name changed?: Yamhill County was created in 1843. Since then the Atlas of Historical County Boundaries records 13 later changes, chiefly involving Washington County, Tillamook County and Clackamas County. It was formerly called Yamhill District.
Is my lot in a flood zone?: We do not have flood maps for Yamhill County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby