Water falling within a watershed is partitioned between a variety tightly coupled reservoirs.  The partitioning, storage and release of water from these reservoirs controls watershed hydrologic function; carbon, geochemical and nutrient budgets; and response to climate change.  Perhaps the least understood reservoirs in the hydrologic cycle are Mountain Aquifer Systems.  These systems present a variety of difficulties hindering instrumentation and monitoring, which limit the amount known about their storage and release mechanics.  To tackle this broad problem, we employ a wide variety of cutting-edge techniques including high-performance computer simulation, isotope hydrology and hydro-geodesy.  In this talk, I will summarize our Lab’s work in trying to delve deeper into mountain aquifer hydrogeology.