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. The value of all farms and ranches for sale in Washington County, Oregon, recently was approximately $216 million, representing a combined 2,312 acres of land for sale in Washington County. Washington County ranks 17th out of 36 counties in the Beaver State for the combined amount of land currently advertised for sale. Of all land and rural real estate for sale in Washington County, 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 the state.