 As of the 2010 census the micropolitan area ranked 2nd most populous in the State of Pennsylvania and the 37th most populous in the United States with a population of 94,528.Northumberland County is also a part of the Bloomsburg–Berwick–Sunbury, PA Combined Statistical Area (CSA), which combines the population of Northumberland County as well as the Columbia, Montour, Snyder and Union County areas.The Combined Statistical Area ranked 8th in the State of Pennsylvania and 115th most populous in the United States with a population of 264,739.