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 combined almost 3,000 acres were listed for sale in Washington County recently; the overall value of all Washington County ranches, farms, hunting land and other rural land and acreage for sale was nearly $220 million. Washington County ranks 17th in the state for the combined amount of land currently advertised for sale. Among cities in Washington County with farms and ranches for sale, Hillsboro featured the most land for sale. Manufacturing and related services are the largest economic sectors in Washington County. Washington County is Oregon's 31st biggest county (726 square miles). It's located in the Portland Metro Oregon region of the state.