Significant environmental degradation has occurred in the Lower Rio Grande Valley (LRGV) of South Texas over the past 40 years. Land use maps allow assessment of environmental loss and serve as a basis for planners to minimize future impacts. A 1995 land use map compares the LRGV with 1960 data and quantifies the various changes. Most striking is the appearance of an incipient megalopolis in an area that was once brush and woodland.