Colorado Department of Local Affairs Field Regions. This layer was created by dissolving Colorado County boundaries. The county outlines in this coverage were digitized from the USGS Colorado County topographic series (1979) scale stable 1:50,000 film positive composites. The digitial boundaries were appended to create the statewide coverage. Includes the 1989 land transfer between Adams and Denver Counties for Denver International Airport and the 2001 formation of Broomfield County.