There are 7 US Post Offices in Yuma County serving a total of 9,949 residents equating to 1,421 residents per post office. It's estimated that approximately 15,880 packages are handled across the 7 county post offices annually. Yuma County is one of the 64 counties of the U.S. state of Colorado. As of the 2010 census, the population was 10,043. The county seat is Wray."