Isotopic and temperature measurements from large, cold springs in the central Oregon Cascades are used to understand where this water comes from and how old it is. In particular, we employ the isotopes of helium, carbon, oxygen, and hydrogen to address these issues and to understand some aspects of the subsurface geology in this region. we find that large, cold springs in the central Oregon Cascades are recharged near the Cascades crest up to 50 km from the springs. We also find that the large springs in the study area discharge water that is a few years old. Finally, we show that deeply circulating groundwater advectively transports geothermal heat and magmatic volatiles to several of the springs such as the Metolius River and Lower Opal Springs.