Oregon

Washington

600,372
2020 population
1850
first census record
18
census records

About Washington

Washington, Oregon, first appears in the United States federal census in 1850, when it recorded a population of 2,652. At the most recent census, in 2020, its population stood at 600,372.

The county's recorded population has risen across the decades to its highest level in 2020.

On the ground today, 51 places are listed on the National Register of Historic Places.

Population by decade

Census YearPopulationChart
2020600,372
2010529,710
2000445,342
1990311,554
1980245,808
1970157,920
196092,237
195061,269
194039,194
193030,275
192026,376
191021,522
190014,467
189011,972
18807,082
18704,261
18602,801
18502,652
Source

Population data from the United States decennial census, U.S. Census Bureau (public domain).

Historic places in Washington

National Register of Historic Places listings in Washington, Oregon.

Dundee Lodge
Gaston
Shorey, Charles, House
Hillsboro
Doriot-Rider Log House
Tigard
First Church of Christ Scientist
Forest Grove
Linklater, Zula, House
Hillsboro
Imbrie Farm
Hillsboro
Blanton, M. E., House
Aloha
Shaver-Bilyeu House
Tigard
Schulmerich, Edward, House
Hillsboro
Shute-Meierjurgen Farmstead
Hillsboro
Oleson, Ole and Polly, Farmhouse
Portland
Ray, Harold Wass, House
Hillsboro
Rice-Gates House
Hillsboro
Old Scotch Church
Hillsboro
Walker Naylor Historic District
Forest Grove
Smith, Alvin T., House
Forest Grove
Rice, Richard and Helen, House
Hillsboro
Clark Historic District
Forest Grove
Mertz, C.W., Rental House #2
Forest Grove
Manning-Kamna Farm
Hillsboro
Painter's Woods Historic District
Forest Grove
Beeks, Silas Jacob N., House
Forest Grove
Fanno, Augustus, Farmhouse
Beaverton
Beaverton Downtown Historic District
Beaverton
Browse all Oregonhistoric sites ›

Other counties in Oregon

Explore census history and historic records for more Oregon counties.

WallowaWascoWheelerYamhillBakerBentonClackamasClatsopColumbiaCoosCrookCurryDeschutesDouglasGilliamGrantHarneyHood RiverJacksonJefferson
Unlimited access

Everything a full report reveals about Washington County, Oregon

This page charts the census history of Washington County, Oregon. A full Aubrey report for an address here pulls together everything the historical record holds about the ground, from the earliest settlement to the twentieth century:

Overview
An interactive map of the location with historic sites, battles and Native heritage plotted, and its full story era by era.
The Land
The historic sites and place names around the location, and how this land was settled and used.
Geology
The bedrock beneath the site, its age and rock type, reaching back millions of years.
LiDAR Terrain
Laser-scanned terrain that reveals earthworks and old features hidden in the landscape.
Conflict & War
The battles, raids and skirmishes fought near here, across every era of American conflict.
The Civil War
The Civil War on this ground, 1861 to 1865: who held it, and the battles, camps and regiments nearby.
The Soldiers
The men who marched from here in the Civil War, named and traced where the record allows.
Native Heritage
The Native nations who held this land, mapped across time from before European contact to today.
Settlement
Who claimed and held this ground, from Indigenous homelands through the colonial powers to the United States.
The Community
How the town grew, who came, and what kind of place it became, traced through the census record.
Rivers & Rail
The rivers, canals and railroads that connected this place between 1830 and 1911.
Notable People
The people born, buried or genuinely tied to this exact place, with their stories.
Historical Maps
Historic maps of the location layered over how it looks today.
Finds & Access
Museum objects tied to the area, and the laws on searching, collecting and access here.
Literature
The old books, county histories and archives that mention this place, quoted with their sources.
Spotlight
A deep dive into the most remarkable, lesser-known history of the place, traced back to the record.
Points of Interest
The most significant historic sites and landmarks near the location, and why they matter.
Timeline
The whole story of the location told era by era, from first peoples to the present day.
First month just $5.99, then $11.99 a month. Unlimited locations, cancel anytime.

Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.

Start your Washington County, Oregon report
Or see a real report first

Explore Oregon records

Oregonhistory ›NRHP historic sites ›Notable people from Oregon›

Frequently asked about Washington

When does Washington first appear in the US census?
Washington, Oregon first appears in the federal census in 1850, with a recorded population of 2,652.
What is the population of Washington?
At the most recent federal census (2020), Washington had a recorded population of 600,372.
How many historic places are in Washington?
51 sites are listed on the National Register of Historic Places in Washington, Oregon.
Aubrey Research

Research the history of any US location

Aubrey searches federal archives, archaeological records, historic registers, and primary sources to build a full historical report for any address or place in the United States.

Research your locationView a free sample report