Many academic libraries support the use of Geographical Information Systems (GIS), offering new ways of interacting with geographic resources online. As these libraries host larger amounts of digital data, including maps and GIS, management and access become increasingly important. This article highlights and analyses the work of a group of Ontario University Libraries to inventory, digitize, georeference, and describe historical maps from the Canadian National Topographic Series. Specifically, we discuss the opportunities and challenges in describing these maps using the ISO 19115 standard, and the resulting access improvements which we argue are transformative for map libraries in the digital age. [ABSTRACT FROM AUTHOR]