Planning for the best use of land and its resources should take fully into consideration the long-term consequences of each type of use in order to stretch out most beneficially the well-being of society in the future, and to protect the integrity of the land and its biota. Three kinds of land-use can be distinguished for planning purposes. Reversible land-use leaves the land, after use, essentially as it was before; little or no man-induced modification remains. An example of reversible use in the United States is the designation of certain public lands as Wilderness. Terminal land-use commits the land to a chosen particular use, and any attempt at reversal requires either time-scales that are long compared with the expected lifespan of the social and political institution, or a commitment of resources that is too high for society to consider worth bearing. Examples of terminal land-use are location of metropolises and sites of toxic and/or radioactive waste disposals; by its nature the list grows monotonically. A current source of some social tension arises from the fact that Wilderness designation appears to assign a terminal-use status by legislative fiat, whereas in fact the land is being used reversibly. In between these two extremes of reversible and terminal land-use, the bulk of land-use is sequential, in which each use of land changes its potentials and configurations, and these changes are mainly irreversible. One goal of geologic input to land-use planning is to identify the various pathways along which a given land may be used, in order to extract the greatest benefit to society with the least harm to the land and its life. The proposed planning format consists of identification of (1) types of land, (2) types of use, (3) nature of consumption of resources when (2) acts upon (1), (4) identification of alternative pathways of land recovery to the original or some new state, and (5) due consideration of potentials for future use. Some consumptions are tangible; others, such as consumption of future options, are not. However, all must be considered in deciding how the land should be used, and both internal and environmental costs need to be included in the planning. Predictive methodology for land-use planning and for estimations of uncertainties must be developed to allow for the needs and consequences of both land-use and land recovery. Hardin (1968) spoke of the tragedy of the commons; White (1967) discussed the constraints of the western cultural heritage on our attitude towards our land and its resources. Land-use presents an archetype of the problem of the commons; only by community awareness of the dire consequences of the latent tragedy can effective societal action begin for the stewardship of the commons. Land-use decisions involve value judgement and are problems without technical solutions; but they require technical input, and earth scientists have a major role to play in both providing the input and in pointing out the implications of alternative decisions. ?? 1983.