Edward L. Nickerson 1995 The Mesilla ground-water basin monitoring program was established in 1987 to document hydrologic conditions and establish a long-term, continuous data base to permit future quantitative evaluation of the ground-water flow system and stream/aquifer relations. Data collection is divided into three program elements. These are the (1) Mesilla ground- water basin observation-well program; (2) Mesilla Valley hydrologic sections; and (3) Rio Grande seepage investigations. This report is a compilation of hydrologic data collected for the Mesilla ground- water basin monitoring program during the 1987 through 1992 water years. Hydrologic data presented in the report include well records and water levels for 181 wells; mean daily river stage and ground- water levels at 37 sites; seepage investigations of the Rio Grande from Radium Springs, New Mexico, to El Paso, Texas; and chemical analyses of 29 water samples collected from the Rio Grande. application/pdf 10.3133/ofr95111 en U.S. Geological Survey Selected hydrologic data for the Mesilla ground-water basin, 1987 through 1992 water years, Doña Ana County, New Mexico, and El Paso County, Texas reports