There are 9 US Post Offices in Coos County serving a total of 63,112 residents equating to 7,012 residents per post office. It's estimated that approximately 100,734 packages are handled across the 9 county post offices annually. Coos County /ku\u02d0s/ is a county located in the U.S. state of Oregon. As of the 2010 census, the population was 63,043. The county seat is Coquille. The county was formed from the western parts of Umpqua and Jackson counties. It is named after a tribe of Native Americans who live in the region. Coos County comprises the Coos Bay, OR Micropolitan Statistical Area."