When was Umatilla County founded?

Umatilla County was founded in 1862, formed from Wasco County, and named after Umatilla River, Oregon.

What is the county seat of Umatilla County?

The county seat of Umatilla County is Pendleton.

Is there an online parcel map for Umatilla County?

Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.

Has Umatilla County's boundary or name changed?

Umatilla County was created in 1862 from Wasco County. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Gilliam County, Grant County and Morrow County.

Is my lot in a flood zone?

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

Umatilla County, Oregon: parcels, history and offices

Where it is

Umatilla on the map of Oregon

Oregon has 36 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of Oregon · Umatilla highlighted

History

Formed in 1862 from Wasco County

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

Umatilla County was created from Wasco on September 27, 1862. The county lost territory to the creation of Grant County in 1864 and to the creation of Morrow County in 1885. Creation of Gilliam County on February 25, 1885, eliminated Umatilla's western portion after the county had been divided by Morrow's creation. In 1907, Umatilla exchanged territory with Union County and lost land to Wallowa County.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1862
Umatilla County created Umatilla created from Wasco.
from Wasco
27 September 1862 · Ore. Laws 1862, 2nd reg. sess., p. 91
1864
Lost territory Umatilla lost to creation of Grant.
to Grant
14 October 1864 · Ore. Laws 1864, 3rd reg. sess., p. 43
1885
Lost territory Umatilla lost to creation of Morrow. Creation resulted in Umatilla being divided into two parts encompassing territory both east and west of Morrow. Division remained until 25 February 1885 when creation of Gilliam eliminated the western portion.
to Morrow to Gilliam
16 February 1885 · Ore. Special Laws 1885, 13th reg. sess., pp. 239-243
1885
Lost territory Umatilla lost to creation of Gilliam.
to Gilliam
25 February 1885 · Ore. Special Laws 1885, 13th reg. sess., p. 404
1907
Exchanged territory Umatilla exchanged with Union, lost to Wallowa. Two mistakes in the line as described were corrected on 27 February 1913.
with Union with Wallowa
13 February 1907 · Ore. Laws 1907, gen., 24th reg. sess., ch. 20/pp. 29-31
1913
Boundary clarified Umatilla boundary with Union and Wallowa redefined to correct two mistakes in the boundary description of 13 February 1907 (no change).
with Union with Wallowano change
27 February 1913 · Ore. Laws 1913, gen., 27th reg. sess., ch. 309/pp. 598-600
1967
Boundary clarified Umatilla redefined to substitute "boundary of the state" for middle of the main channel of the Columbia River. Approved by the Governor 19 June 1967, became effective 13 Sep 1967 (no change).
no change
13 September 1967 · Ore. Laws 1967, 54th reg. sess., ch. 421/pp. 929-930

Land and parcels

What the maps cover in Umatilla

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

Parcels Missing

No public parcel map found for Umatilla County yet. Lot lines and owners of record are kept by the county assessor's office.
Address points Official

One point per address, 34,144 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

Umatilla by the Census

Population

80,075 2020 Census count

Housing units

31,098 2020 Census count

Land area

3,215 square miles

Water area

16 square miles

People per sq mi

25 population ÷ land area

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

See your own lot on these maps

Open Umatilla 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 Umatilla County

When was Umatilla County founded?: Umatilla County was founded in 1862, formed from Wasco County, and named after Umatilla River, Oregon.
What is the county seat of Umatilla County?: The county seat of Umatilla County is Pendleton.
Is there an online parcel map for Umatilla County?: Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.
Has Umatilla County's boundary or name changed?: Umatilla County was created in 1862 from Wasco County. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Gilliam County, Grant County and Morrow County.
Is my lot in a flood zone?: We do not have flood maps for Umatilla County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby

Umatilla CountyOregon