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. There was a combined nearly $237 million of farms and ranches for sale in Oregon's Washington County recently on Land.com. The total size of all Washington County farms, ranches, hunting land and other land for sale was around 3,000 acres. Washington County ranks 17th in the Beaver State for the combined amount 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 biggest county (726 square miles) in Oregon. It's located in the Portland Metro Oregon region of Oregon.