Arizona County Creation Dates and Parent Counties

United States Arizona  County Creation Dates

Arizona Territory was created on 24 February 1863. All previous counties were discontinued, but new counties were not immediatly created. Then on 10 November 1864, the first four counties were created. The last county created was La Paz on 27 April 1983. In the present day there are a total of 15 counties.

Arizona Atlas of Historical County Boundaries Detailed information of historical county boundary changes.