The Greater Richmond Region, also known as Richmond-Petersburg and the Richmond metropolitan area, is a region and metropolitan area in the U.S. state of Virginia, centered on Richmond. The U.S. Office of Management and Budget (OMB) defines the area as the Richmond, VA Metropolitan Statistical Area, a Metropolitan Statistical Area (MSA) used by the U.S. Census Bureau and other entities. The OMB defines the area as comprising thirteen counties, including the principal cities of Richmond, Petersburg, Hopewell, and Colonial Heights. As of 2010, it had a population of 1,258,251, making it the 43rd largest MSA in the country.