A growing body of research has illuminated the powerful role played by social capital in influencing disaster and resilience outcomes. Popular vulnerability mapping frameworks, while well suited for capturing demographic characteristics such as age, race, and wealth, do not include sufficient proxies for social capital. This article proposes a concrete way to measure bonding, bridging, and linking social capital using widely available information. Our social capital index (SoCI) uses 19 indicators from publicly available U.S. census and Environmental Systems Research Institute (ESRI) data for all counties across the contiguous United States. We demonstrate broad variations in the SoCI Index by mapping counties across the continental North America. Validity tests indicate outcomes similar or superior to other approaches such as the Baseline Resilience Indicators for Communities (BRIC) and the Social Vulnerability Index (SoVI). Our new mapping framework provides a more focused way for disaster managers, scholars, and local residents to understand how communities could cope with future disasters based on levels of social ties and cohesion.