This digital data set represents the constant head-boundary used to simulate ground-water inflow or outflow at the lateral boundary of the Death Valley regional ground-water flow system (DVRFS) transient model. The area simulated by the DVRFS transient ground-water flow model is an approximately 45,000 square-kilometer region of southern Nevada and California. The hydraulic heads imposed at the constant-head cells were interpolated from a regional potentiometric surface ("Larger Work Citation", Appendix 1). Quantity of ground- water flow at the constant-head boundary was estimated using water-budget and Darcy calculations ("Larger Work Citation", Appendix 2), and was used as observation information during calibration of the DVRFS model (Faunt and others, 2004). The DVRFS transient ground-water flow model is one of the most recent in a number of regional-scale models developed by the U.S. Geological Survey (USGS) for the U.S. Department of Energy (DOE) to support investigations at the Nevada Test Site (NTS) and at Yucca Mountain, Nevada (see "Larger Work Citation", Chapter A, page 8).