Managers of historic sites need to understand their exposure to climatic and environmental change, which varies widely by property type and location. A large and evolving body of science and climate modeling identifies ongoing and future changes with increasing specificity. Changes range from the predictable, like mean temperature and sea-level rise, to the erratic, like storms and wildfires, and may include human adaptive measures like floodwalls and migration. These data can be cross-referenced against site attributes to evaluate risk. Relevant site attributes include location and topography, materials, character-defining features, landscape species, surrounding land uses, and operational needs. This work presents a vulnerability assessment protocol that serves to identify and rank risk in order to inform decision-making about adaptive measures, which can range from choice of repair materials to landscaping to relocation. When applied to a fleet of sites, the protocol can inform policy- and grant-making.