Marriage-mate selection distances are used to operationalize the concept of isolation for three eastern Kentucky counties. Isolation changes between 1900 and 1988 are compared for four periods of economic transformation. The assumption is that short marriage distances occur in isolated areas whereas longer marriage distances reflect a greater spatial range of physical and social contact. Isolation, as defined by marriage-mate selection distances, decreased substantially during the industrial transformation period of 1900-1930 but changed very little between 1930 and 1988. Our findings stand in stark contrast to those of Ford (1962) who argued that factors such as education, mass communication, and improved roads have helped to reduce isolation in the southern Appalachian region.