Recharge in the Death Valley regional ground-water flow system (DVRFS) was estimated from net infiltration simulated by Hevesi and others (2003) using a deterministic mass-balance method. Hevesi and others (2003) estimated potential recharge for the DVRFS, an approximately 100,000 square-kilometer region of southern Nevada and California, using the net-infiltration model, INFILv3. Net infiltration, estimated on a cell-by-cell basis, equaled the sum of snowmelt, precipitation, and infiltrating surface flow minus the sum of evapotranspiration (ET), runoff, and changes in root-zone storage. The net-infiltration model was calibrated to available surface-water flow measurements and constrained by prior estimates of recharge and discharge. The calibrated net-infiltration model (model 1 in Hevesi and others, 2003) was used to simulate daily net infiltration from 1950 through 1999 across the DVRFS model domain (San Juan and others, 2004) and was also used as a component of recharge in the DVRFS transient ground-water flow 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).