There are 6 US Post Offices in Baca County serving a total of 3,803 residents equating to 634 residents per post office. It's estimated that approximately 6,070 packages are handled across the 6 county post offices annually. Baca County is the southeasternmost of the 64 counties in the U.S. state of Colorado. As of the 2010 census, the population was 3,788. The county seat is Springfield."