Geologic Resources Inventory reports provide information and resources to help park managers make decisions for visitor safety, planning and protection of infrastructure, and preservation of natural and cultural resources. Information in GRI reports may also be useful for interpretation. This report synthesizes discussions from a scoping meeting held in 2007 and a follow-up conference call in 2020. Chapters of this report discuss the geologic heritage, geologic features and processes, and geologic resource management issues of John Muir National Historic Site. Guidance for resource management and information about the previously completed GRI map data is also provided. A GRI map poster (separate product) illustrate the GRI map data. Geologic features, processes, and resource management issues identified include the Great Valley sequence, an unconformity, the Martinez Formation, the San Andreas Fault, an anticline, fluvial features and processes, erosion, flooding, slope movements, earthquakes, climate change, and paleontological resources.