These data were created to describe the causes of land cover change that occurred in the Lower Rio Grande (LRG) Valley and Alluvial Floodplain ecoregions of Texas for the time intervals of 2001 to 2006 and 2006 to 2011. The study area covers approximately 600,000 hectares at the southernmost tip of Texas and is one of the fastest growing regions in the United States. Some of the largest cities in the area include Brownsville and Harlingen, Texas. Two raster maps showing the causes of land change were created at a 30-meter resolution using automated and manual photo interpretation techniques. There were 26 categories of land change causes (for example, urban expansion or surficial mining) identified across the LRG region. These categories can be used by researchers to summarize the historical patterns of land change for the region and to understand the impacts these land change causes may have on the region's ecology, hydrology, wildlife, and climate.