Land subsidence and earth fissuring have occurred in large portions of south ern Arizona, where they have caused a variety of structural damage and landmanagement problems. As Arizona’s population continues to increase, so wifi the demand for ground water. Subsi dence and earth fissuring wifi continue, extend into new areas, and create addi tional problems. The purpose of this report is to describe, in terms that are understandable to persons who are not trained in geology, what land subsidence and earth fissures are, why they develop, where they occur, what kinds of prob lems they create, and what can be done about them. Dedicated to the memory of Cathy Schulten Wellendorf (1956-1988).