Washington County is one of 36 counties in the U.S. state of Oregon and part of the Portland metropolitan area. The 2020 census recorded the population as 600,372, making it the second most populous county in the state and most populous "Washington County" in the United States. Hillsboro is the county seat and largest city, while other major cities include Beaverton, Tigard, Cornelius, Banks, Gaston, Sherwood, North Plains, and Forest Grove, the county's oldest city. Originally named Twality when created in 1843, the Oregon Territorial Legislature renamed it for the nation's first president in 1849 and included the entire northwest corner of Oregon before new counties were created in 1854. The Tualatin River and its drainage basin lie almost entirely within the county, which shares its boundaries with the Tualatin Valley. It is bordered on the west and north by the Northern Oregon Coast Range, on the south by the Chehalem Mountains, and on the north and east by the Tualatin Mountains, or West Hills.
Cedar Mill is a suburb in the Portland, Oregon metropolitan area of the United States; it is a census-designated place and an unincorporated community in Washington County, north of U.S. Route 26 and west of the Willamette Stone. It received its name from a sawmill on Cedar Mill Creek, which cut Western Redcedars that were once the dominant tree in the area. The mill's pond was near the intersection of 119th and Cornell Road, and could still be seen into the 1960s, although the mill itself had ceased operating in 1891. The name was established in 1874 with the opening of a U.S. post office named Cedar Mill. As of the 2010 census, the community population was 14,546.
Cornelius is a city in Washington County, Oregon, United States. Located in the Portland metropolitan area, the city's population was 11,869 at the 2010 census. The city lies along Tualatin Valley Highway between Forest Grove to the west and Hillsboro to the east. Cornelius was incorporated in 1893 and is named for founder Thomas R. Cornelius.
Forest Grove is a city in Washington County, Oregon, United States, 25 miles (40 km) west of Portland. Originally a small farm town, it is now primarily a commuter town in the Portland metro area. Settled in the 1840s, the town was platted in 1850, then incorporated in 1872, making it the first city in Washington County. The population was 21,083 at the 2010 census, an increase of 19.1% over the 2000 figure (17,708).
Gaston is a city in Washington County, Oregon, United States. Located between Forest Grove to the north and Yamhill to the south, the city straddles Oregon Route 47 and borders the Tualatin River. Named after railroad executive Joseph Gaston, its population was 637 as of the 2010 census.
Hillsboro is the 5th most populous city in the U.S. state of Oregon and is the county seat of Washington County. Situated in the Tualatin Valley on the west side of the Portland metropolitan area, the city hosts many high-technology companies, such as Intel, locally known as the Silicon Forest. At the 2020 census, the city's population was 106,447.
The Tualatin River is a tributary of the Willamette River in Oregon in the United States. The river is about 83 miles (134 km) long, and it drains a fertile farming region called the Tualatin Valley southwest and west of Portland at the northwest corner of the Willamette Valley. There are approximately 500,000 people residing on 15 percent of the land in the river's watershed.
The Tualatin Valley is a farming and suburban region southwest of Portland, Oregon. The valley is formed by the meandering Tualatin River, a tributary of the Willamette River at the northwest corner of the Willamette Valley, east of the Northern Oregon Coast Range. Most of the valley is located within Washington County, separated from Portland by the Tualatin Mountains. Communities in the Tualatin Valley include Banks, Forest Grove, Cornelius, Hillsboro, Aloha, Beaverton, Sherwood, Tigard, and Tualatin.
Orenco is a former company town in Washington County, Oregon, United States, located between Hillsboro and Aloha. The former community of Orenco now forms the Orenco neighborhood in Hillsboro, which is the site of the Orenco Station housing development.
The Tualatin Valley Highway No. 29 is an Oregon highway which passes through the Tualatin Valley, between the cities of McMinnville and Beaverton. Between McMinnville and Forest Grove, the highway is signed as Oregon Route 47; between Forest Grove and Beaverton it is signed as Oregon Route 8. Oregon 8 becomes Canyon Road in Beaverton east of Hocken Road.
Laurelwood is an unincorporated community in Washington County, Oregon, United States. The community is located southwest of the Portland metropolitan area near Oregon Route 47 along Laurelwood Road, to the east of the city of Gaston and Wapato Lake. Laurelwood, a farming community, has a population of approximately 500 people. Settled in the 1860s, the community was home to Laurelwood Academy from 1904 until 2007. A large portion of the community is of the Seventh-day Adventist faith.
Cherry Grove is an unincorporated community in Washington County, Oregon, United States. Cherry Grove is situated on the north bank of the Tualatin River near where it exits the Northern Oregon Coast Range and enters Patton Valley.
Clean Water Services is the water resources management utility for more than 600,000 residents in urban Washington County, Oregon and small portions of Multnomah County, Oregon and Clackamas County, Oregon, in the United States. Clean Water Services operates four wastewater treatment facilities, constructs and maintains flood management and water quality projects, and manages flow into the Tualatin River to improve water quality and protect fish habitat. They are headquartered in Hillsboro.
West Union is an unincorporated community in Washington County, Oregon, United States. Founded in 1851, the community had the first school district in the county; it also contains the oldest cemetery in the state and the oldest Baptist church west of the Rocky Mountains. It is located north of Hillsboro near the intersection of West Union Road and Cornelius Pass Road north of the Sunset Highway. The name comes from a grove of five oak trees that was used as a meeting place of early settlers, or the "union of the west." West Union had a post office from 1874 to 1894.
The Tualatin Plains are a prairie area in central Washington County, Oregon, United States. Located around the Hillsboro and Forest Grove areas, the plains were first inhabited by the Atfalati band of the Kalapuya group of Native Americans. Euro-American settlement began in the 1840s.
Glencoe is a neighborhood and former community in Washington County, Oregon, United States. Founded in 1842, the town, which was north of Hillsboro, died off after 1910 when neighboring North Plains was created to the west. Most of Glencoe is now a part of North Plains. Glencoe gives its name to the road connecting Hillsboro to North Plains, as well as the name of the second high school built in Hillsboro, Glencoe High School.
The Alvin T. Smith House is a two-story home on Elm Street in Forest Grove, Oregon, United States. Completed in 1856, it is the second oldest building in the city and was added to the National Register of Historic Places in 1974. A Greek Revival style house, it was built by pioneer Alvin T. Smith beginning in 1854.
Laurel is an unincorporated community in Washington County, Oregon, United States. Settled in 1872, the community is located between Hillsboro and Newberg, in the southern portion of the Tualatin Valley in the foothills of the Chehalem Mountains. The community retains its agricultural heritage. Laurel is served by the Hillsboro School District and includes the century-old Laurel Valley Store building, which is in the process of being turned into a restaurant. As an unincorporated community, Laurel has no defined boundaries or population statistics of its own.
Alvin Thompson Smith was an American missionary and politician in what became the state of Oregon. A native of Connecticut, he lived in Illinois before moving to the Oregon Country to preach to the Native Americans in the Tualatin Valley. There he served in both the Provisional Government of Oregon and the government of the Oregon Territory, as well as helping to establish Tualatin Academy, later becoming Pacific University. Smith's former home, the Alvin T. Smith House in Forest Grove, is listed on the National Register of Historic Places.
Verboort is an unincorporated community in Washington County, Oregon, United States. It is located approximately two miles northeast of Forest Grove, one mile east of Oregon Route 47 in the Tualatin Valley. The community is part of the Forest Grove Rural Fire Protection District.
