Twenty-first-century global warming poses a significant threat to the cultural heritage of coastal regions, but the effects of sea-level rise and changing weather patterns will not be evenly distributed. In addition, continued urban, agricultural, and industrial development concentrated in coastal areas contributes to the destruction of cultural resources. Mitigation of these threats requires rapid action on the part of archaeologists and public land managers. This study presents a method for quickly evaluating relative resource vulnerability at national, regional, and local scales, using data that is available for all United States coastlines, as well as many other coastlines around the world. Three regional case studies-the mountainous coast of California's Santa Barbara Channel, the wetlands and sandy shores of Texas, and the protected estuarine shores of Virginia's Chesapeake Bay-are compared to shoreline vulnerability for the United States as a whole. In each of these regions, sites have already been submerged under rising tides, lost to storm erosion, or destroyed by human activities. Variability in coastal geomorphology, rates of relative sea-level rise, and the structure of prehistoric settlement and subsistence systems, however, produce different patterns of vulnerability.