This digital data set defines the flow-system boundary encompassing the regional ground-water flow model by D'Agnese and others (1997). The boundary encompasses an approximately 50,000 square-kilometer region of southern Nevada and California, defined as the Death Valley region by Bedinger and others (1989; see Source Citation Information). The flow-system boundary is mostly a no-flow boundary resulting from physical barriers or hydraulic separation of flow regimes (ground-water divides or regional flow lines). D'Agnese and others (1997) used results from the evaluation of flow-system components, such as recharge, discharge and hydrogeologic framework, to develop the ground-water flow model of the Death Valley regional ground-water flow system (DVRFS) to support investigations at Yucca Mountain, Nevada, for the U.S. Department of Energy. The regional ground- water flow model was also the basis of development for a transient-flow model of an expanded DVRFS region that was completed in 2004 by the U.S. Geological Survey (see "Larger Work Citation", Chapter A, pages 7-8, for details).