Abstract: The University of North Texas Libraries and its partner, the University of Texas at Arlington’s Special Collections, are working on a 3-year (2010 to 2013) collaborative “Mapping the Southwest” project, sponsored by a National Endowment for the Humanities (NEH) We the People grant. For this project we are digitizing 5,000 historically-significant maps and more than 80% are already processed and available online for free public access through The Portal to Texas History. All of the maps digitized for this grant meet the UNT metadata requirements, which means that all are Open Archive Initiative-Protocol for Metadata Harvesting (OAI-PMH) harvestable, and are interoperable or compliant with widely adopted standards (such as Dublin Core, MARC, MODS, and PREMIS). On the Portal, users can find materials using a basic search, an advanced search, or through multiple browse interfaces. Digital object display on the Portal has been optimized for indexing by Google and other search engines. Overall, 44% of all traffic to the Portal is referred from search engines such as Google, MSN, Yahoo, etc. To attract lay people to the good quality resources in our collections, we have also added extensive external links into our digital materials from Wikipedia, which has resulted in significant increases in usage of the collections. Among other digital libraries functionalities, when users find maps in the Portal, the maps manifest within a zoom feature that does not require any special downloads or software. The zooming software works with Flash Player, which is ubiquitous, reaching 99% of Internet users. The zooming feature allows users to see every detail of the map; grab and move the map with a click and pull mouse motion; or move the area of selection by dropping and dragging the selection area on the object icon. As we approach the project completion phase, this poster describes the lessons learned, and project impact not only in terms of showcasing the cartography of the region, but also in promoting best practices and advancing the capacity of academic libraries to reliably curate, preserve, and provide seamless access to such wide-format items to the diverse global user community.