There are 5 US Post Offices in Owyhee County serving a total of 10,138 residents equating to 2,028 residents per post office. It's estimated that approximately 16,181 packages are handled across the 5 county post offices annually. Owyhee County is a county located in the southwestern corner of the U.S. state of Idaho. As of the 2010 census, the population was 11,526. The county seat is Murphy, and its largest city is Homedale. In area it is the second-largest county in Idaho, behind Idaho County. Owyhee County is part of the Boise, ID Metropolitan Statistical Area."