Ada County is located in the southwestern part of the U.S. state of Idaho. As of the 2010 United States Census, the county had a population of 392,365, making it the state's most populous county, with 23.3% of the state's 2010 population. The county seat and largest city is Boise, which is also the state capitol.

Oneida County is not organized, contact morgan@idahodems.org for more information.