There are 22 US Post Offices in Tulsa County serving a total of 444,872 residents equating to 20,221 residents per post office. It's estimated that approximately 710,065 packages are handled across the 22 county post offices annually. Tulsa County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 603,403, making it the second-most populous county in Oklahoma, behind only Oklahoma County. Its county seat and largest city is Tulsa, the second-largest city in the state. Founded at statehood, in 1907, it was named after the previously established city of Tulsa. Before statehood, the area was part of both the Creek Nation and the Cooweescoowee District of Cherokee Nation in Indian Territory. Tulsa County is included in the Tulsa, OK Metropolitan Statistical Area. Tulsa County is notable for being the most densely populated county in the state. Tulsa County also ranks as having the highest-income."