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 almost 3,000 acres were listed for sale in Oregon's Washington County recently; the overall value of all Washington County farms, ranches, and rural real estate for sale was around $224 million. Washington County ranks 16th in the Beaver State for the total acreage of land currently advertised for sale. Of all locations in Washington County with farms and ranches for sale, Hillsboro had the most land for sale. From an economic perspective, manufacturing and related services are the main 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.