The phenomenon of rural depopulation has been an intense and centuries-long process in the mountain areas of Aragon in Spain. Throughout the nineteenth century, the traditional economic model of these territories broke down due to the crisis suffered by seasonal sheep migration, the non-viability of the old forms of agricultural production based on self-sufficiency and the destruction of the scattered textile industry. The new scenario offered some possible alternatives in sectors such as livestock, timber, mining and energy production or the activities associated with tourism and second homes. However, it is only these latter activities that have demonstrated some capacity to alter significantly the demographic tendencies, and even then they have done so in a somewhat delayed fashion and in a way limited to a small proportion of the geographical areas under study.