There are 3 US Post Offices in Boise County serving a total of 4,791 residents equating to 1,597 residents per post office. It's estimated that approximately 7,647 packages are handled across the 3 county post offices annually. Boise County is a rural mountain county in the U.S. state of Idaho. As of the 2010 census, the population was 7,028. The county seat is Idaho City, and Horseshoe Bend is its largest city. Boise County is part of the Boise, ID Metropolitan Statistical Area. The Bogus Basin ski area is in the southwestern part of the county. The county's eastern area contains the central section of the Sawtooth Wilderness, the western part of the Sawtooth National Recreation Area. In 2010, the center of population of Idaho was located in Boise County."