USDA’s Economic Research Service recently constructed a new set of regions depicting geographic specialization in production of U.S. farm commodities. With more and more data available at the county level, geographic representations need no longer be constrained to follow State boundaries. ERS will use the new regions to display results of its analyses in a broad array of venues—from briefings to publications, our Web site, and journal articles. The new regions take advantage of both new capabilities and standards in the resolution of the data we work with and overcome some longstanding problems with the old USDA Farm Production Regions. This pamphlet introduces the Farm Resource Regions, explains their origin and rationale, and serves as a reference for our clients.