Boise County is a rural mountain county in the U.S. state of Idaho. As of the 2020 United States Census, the population was 7,610. The county seat is historic Idaho City, which is connected through a series of paved and unpaved roads to Lowman, Centerville, Placerville, Pioneerville, Star Ranch, Crouch, Garden Valley, and Horseshoe Bend. Boise County is part of the Boise, ID Metropolitan Statistical Area. The Bogus Basin ski area is in the southwestern part of the county.