Large-scale data integration efforts to support clinical and biologic research are greatly facilitated by the adoption of standards for the representation and exchange of data. As part of a larger project to design the necessary architecture for multi-institutional sharing of disparate biomedical data, we explored the potential of the HL7 Reference Information Model (RIM) for representing the data stored in a local academic clinical data warehouse. A necessary first step in information exchange with such a warehouse is the development and utilization of tools for transforming between local data schemas and standards-based conceptual data models. We describe our initial efforts at mapping clinical concepts from a relational data warehouse to the HL7 RIM.