There are 9 US Post Offices in Lincoln County serving a total of 10,689 residents equating to 1,188 residents per post office. It's estimated that approximately 17,061 packages are handled across the 9 county post offices annually. Lincoln County is a county located in the U.S. state of Washington. As of the 2010 census, the population was 10,570, making it the fifth-least populous county in Washington. The county seat and largest city is Davenport. The county was created out of Whitman County on November 24, 1883 and is named for Abraham Lincoln, 16th President of the United States."