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 2,000 acres were listed for sale in Washington County, Oregon, recently, representing a combined around $194 million in Washington County farms and ranches for sale. Washington County ranks 16th in the state for the total acreage of land currently advertised for sale. Of all land for sale in Washington County, Hillsboro had 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 the state.