Washington County, Oregon, United States

🇺🇸 Washington County is one of the 36 counties in the U.S. state of Oregon. It is the state's second most populous county. The county seat and largest city is Hillsboro. Washington County is part of the Portland metropolitan area. Cities in Washington County include Hillsboro, Beaverton, Tigard, Cornelius, Banks, Gaston, Sherwood, North Plains, and Forest Grove, the county's oldest city.

Originally named Twality when created in 1843, the territorial legislature renamed it for the nation's first president in 1849. The original boundaries included the entire north-west corner of Oregon before sections became new counties. The Tualatin River and its drainage basin are almost entirely within the county, with the county nearly coterminous 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).

The county's major roads include small sections of Interstate 5 and Interstate 205, the Sunset Highway, Oregon Route 217, Oregon Route 47, Oregon Route 10, Oregon Route 6, and Oregon Route 8. Public transportation is primarily operated by TriMet and includes buses, the Westside Express Service commuter rail, and MAX Light Rail. Other transportation includes air travel at the Hillsboro Airport, private airfields and heliports, and heavy rail cargo on rail lines.

History The Provisional Legislature of Oregon created the county as Twality District on July 5, 1843. Twality was one of the original four districts of the Provisional Government of Oregon in Oregon Country along with Clackamas, Champooick (later Marion), and Yamhill counties. Columbia, later known as Hillsboro, was selected as the county seat in 1850. Washington County lost significant portions of its original area when Columbia and Multnomah counties were created in 1854. The county area was increased by 160 acres (65 ha) in 2014 when a section of Multnomah County was attached to Washington. The area was returned to Washington County to allow for property development.

The construction of Canyon Road to Beaverton helped Portland to consolidate its position as the primary port of Oregon, and defeat the rival efforts of settlements such as Oregon City and Milwaukie.

In November 2004, the County and the City of Beaverton agreed to a plan where the city would annex both unincorporated residential neighborhoods as well as high-value areas of land. This would result with Cedar Hills, Garden Home, Raleigh Hills, West Slope being incorporated by 2010, and the communities of Aloha, Bethany, and Cedar Mill at some point after that.

Those plans have since been put on hold after Beaverton attempted to annex Nike, Inc.'s World Headquarters, which would have increased Nike's taxes substantially. Nike successfully lobbied the legislature for a law that would prohibit their annexation for 99 years. Since that decision, annexation plans have been halted, and Washington County started urban planning to provide city-level services to the unincorporated urban areas in the county.

Geography According to the United States Census Bureau, the county has a total area of 726 square miles (1,880 km²), of which 724 square miles (1,880 km²) is land and 2.2 square miles (5.7 km²) (0.3%) is water. It is located approximately 20 miles (32 km) to the west of Portland. The Portland Metro Urban Growth Boundary (UGB) bisects the county. The county's highest point is South Saddle Mountain at 3,464 feet (1,056 m) above sea level in the Northern Oregon Coast Range.

Most of the county is in the Tualatin Valley, formed by the Tualatin Mountains to the east and north, the Chehalem Mountains to the south, and the Northern Oregon Coast Range to the west and north. The Tualatin River, located almost entirely within the county, flows through the Tualatin Plains. The northern and western portions of the county are forested, while the remainder of the county includes urban areas, agricultural lands, and floodplains.

Waterways The Tualatin River is the main river in Washington County. Henry Hagg Lake, south-west of Forest Grove, is the largest lake. The Willamette River lies to the east, the Columbia River to the north-east, and the Pacific Ocean to the west of the county.

Adjacent counties • Clatsop County - northwest • Columbia County - north • Multnomah County - east • Clackamas County - southeast • Yamhill County - south • Tillamook County - west

Major highways • Interstate 5 (freeway) • Interstate 205 (freeway) • U.S. Route 26 (freeway for part) • Oregon Route 6 • Oregon Route 8 • Oregon Route 10 • Oregon Route 47 • Oregon Route 99W • Oregon Route 210 • Oregon Route 217 (freeway) • Oregon Route 219

National protected areas • Tualatin River National Wildlife Refuge (part).

Economy Washington County is centered on a fertile plain that attracted farmers before the first wagon trains. In 1997, orchards covered 8,403 acres (34.01 km²) of the county's lands and 1,163 acres (4.71 km²) were devoted to vineyards. Agriculture is still a major industry in Washington County, as are lumber, manufacturing, and food processing.

The development of a large electronics industry during the 1980s and 1990s is the dominating factor of the county economy, and contributing to the creation of Oregon's Silicon Forest. California-based Intel, Oregon's largest private-sector employer, has its largest concentration of employees in the county, mainly in Hillsboro. Other technology companies include Electro Scientific Industries, FEI Company, Qorvo, Tektronix, SolarWorld, Planar Systems, and EPSON.

Nike, one of two Fortune 500 corporations based in Oregon, has its headquarters in Washington County. Until it was acquired by IBM, Sequent Computer Systems was headquartered near Nike. Other companies with headquarters in Washington County include optical instruments manufacturer Leupold & Stevens, Columbia Sportswear, and Reser's Fine Foods.