Washington County is part of the the Chehalem Mountains AVA wine region, which sits on a series of sedimentary ridges that provide diverse soils and growing conditions at slightly higher altitudes than other Willamette Valley vineyards. Some 150 vineyards are located throughout the hilly countryside, comprising three counties—Yamhill, Washington and Clackamas—which frame the southwestern suburbs of the Portland metropolitan area. A total of approximately 3,000 acres were listed for sale in Oregon's Washington County recently, representing a total value of $217 million in Washington County land for sale. Washington County ranks 17th in the Beaver State for the total number of acres of land currently advertised for sale. Of all locations in Washington County with farms, ranches, hunting land and other land for sale, Hillsboro featured the most land for sale. Manufacturing and related services are the largest economic sectors in Washington County. Washington County is the 31st largest county (726 square miles) in Oregon. It's located in the Portland Metro Oregon region of Oregon.