Many scientific disciplines need to locate, digitize, and integrate the collections of historical ecological data that often remain hidden in paper archives. Synthesizing historical and contemporary ecological data with ecosystem models can help researchers understand how species, communities, and landscapes are changing across space and time. Since these data are often stored in multiple collections and in various formats, data integration can be challenging. This paper presents a case study of the digitization of a large historical vegetation survey, i.e., the Wieslander Vegetation Type Mapping (VTM) project in California which highlights the importance of recovering and sharing such datasets. The protocol developed to digitize, georeference, visualize, and share these data is founded in geospatial concepts, and the VTM project showcases the increasingly important role of geospatial experts in the fields of ecology, history, and other sciences. These methods are flexible, transferable and broadly applicable to other fields.