"Mammals of the San Gabriel Mountains of California" by Terry A. Vaughan is a scientific publication written in the mid-20th century. The text provides an extensive survey of the mammalian fauna in the San Gabriel Mountains, aimed at cataloging species and examining their geographic and ecologic ranges. The work underscores the complexity of the area's ecosystems and highlights the interactions between different animal species and their habitats. The opening of the publication introduces the study's context, focusing on the various biotic provinces within the San Gabriel Mountains. Vaughan shares details about the methodologies employed to gather data, including fieldwork conducted from 1948 to 1952. As he outlines the geographical features and climatic variations of the region, he sets the stage for a comprehensive assessment of the various ecological associations and the species inhabiting them. The introduction also indicates the extensive research done to document over 350 mammalian specimens, establishing the groundwork for a detailed and scientifically rich analysis of mammal populations in this vital ecosystem. (This is an automatically generated summary.)