This digital data set defines the boundary of the ground-water flow model by D'Agnese and others (1997). This steady-state, 3-layer ground-water flow model was developed by the U.S. Geological Survey (USGS) for the U.S. Department of Energy (DOE) to support investigations at Yucca Mountain, Nevada (see "Larger Work Citation", Chapter A, pages 7-8, for details). The model area encompasses approximately 35,000 square-kilometers of southern Nevada and California, or most of the Death Valley regional ground-water flow system (DVRFS) defined by D'Agnese and others (1997). Where possible, the lateral boundary encompassing the model area is a no-flow boundary resulting from physical barriers or hydraulic separation of flow regimes (ground-water divides or regional flow lines). Three major subregional flow systems are defined within the model area and represent areas where regional ground-water flow moves from recharge areas in Nevada to discharge areas in Death Valley.