The North American Regional Climate Change Assessment Program (NARCCAP) is an international effort to produce high resolution climate change scenarios and investigate uncertainties in regional scale projections of future climate by nesting multiple regional climate models (RCMs) within multiple atmosphere-ocean general circulation models (AOGCMs) forced with the A2 SRES scenario over a domain covering the conterminous United States and most of Canada. The resulting datasets will total roughly 60 terabytes in size and must be archived for distributed storage and made available to global change impacts researchers worldwide via the Earth System Grid (ESG). This presentation will describe our data management procedures and the lessons we have learned along the way about handling this data flux, maintaining its quality and integrity, and ensuring that the final product is usable by the impacts community, GIS practitioners, climate analysts, modelers, policy-makers, and other end users. The importance of data formats, metadata standards, and flexible tools for visualization, checking, and automation will be discussed, as will social and other significant factors.