Concerns that the loss of habitat have greatly increased species extinction rates has led to calls for establishing biological reserves to preserve key habitat. In this paper, we study reserve site selection for terrestrial vertebrates in Oregon using data on species ranges and land values. We find cost-effective strategies that represent a maximum number of species for a given conservation budget. By varying the budget, we find the cost of obtaining various levels of representation. In general, effective conservation decision-making requires integrated analysis of both biological and economic data.