MAPping out the Future from the Past

Mountain West Digital Library (MWDL) was founded in 2001 and offers a public search portal supporting discovery of over a million items from digitized historical collections throughout the US Mountain West. This aggregation work necessitates a metadata application profile (MAP) to ensure metadata consistency and interoperability from the regional member network of libraries, archives, and cultural heritage organizations. Unique issues arise in combining metadata from diverse local digital repository platforms and aggregation technology infrastructure introduces further constraints, challenges, and opportunities. Upstream aggregation of metadata in the Digital Public Library of America (DPLA) also influences local and regional metadata modeling decisions. This article traces the history of MWDL's MAPs, comparing and contrasting five published standards to date. In particular, it will focus primarily on decisions and changes made in the most recent version, published in early 2020.