Northwest Arkansas (NWA) is a metropolitan area and region in Arkansas within the Ozark Mountains. It includes four of the ten largest cities in the state: Fayetteville, Springdale, Rogers, and Bentonville, the surrounding towns of Benton and Washington counties, and adjacent rural Madison County, Arkansas. The United States Census Bureau-defined Fayetteville–Springdale–Rogers Metropolitan Statistical Area includes 3,213.01 square miles (8,321.7 km2) and 560,709 residents (as of 2021), ranking NWA as the 102nd most-populous metropolitan statistical area in the U.S. and the 13th fastest growing in the United States.