Tulsa is the second-largest city in the state of Oklahoma and 47th-most populous city in the United States. As of July 2014, the population was 399,682, an increase of 7,776 over that reported in the 2010 Census. It is the principal municipality of the Tulsa Metropolitan Area, a region with 961,561 residents in the MSA and 1,131,458 in the CSA. The city serves as the county seat of Tulsa County, the most densely populated county in Oklahoma, with urban development extending into Osage, Rogers, and Wagoner counties.