"The prison construction boom was not concentrated in a few, key states or in certain regions of the country. Prison systems expanded significantly in states across the country. Prison systems also expanded within states. The share of counties in the top 10 states that were home to at least one prison increased from 13 to 31 percent between 1979 and 2000. State level maps (figures 13 to 22) illustrate that new prisons were geographically dispersed throughout the states. New prisons were generally not spatially concentrated, as few counties gained three or more prisons. Finally, prisons expanded into different types of counties; prisons increased significantly in both non-metro counties and metro counties."
Lawrence, Sarah and Jeremy Travis. The New Landscape of Imprisonment: Mapping America's Prison Expansion. Washington, DC: Urban Institute, April 2004.