Radiogenic isotopes of strontium and uranium (87Sr/86Sr and 234U/238U) are useful tracers of water-rock interactions. Sr isotopic signatures in groundwater are derived by dissolution or exchange with Sr contained in aquifer rock whereas U isotopic signatures are more controlled by physicochemical and kinetic processes during groundwater flow. Insights into groundwater circulation patterns through the shallow subsurface at Yellowstone National Park can be aided by investigations of these isotopes. This data release contains tables with new isotope data consisting of concentrations (Sr, U) and radiogenic-isotope compositions (87Sr/86Sr, 234U/238U) for samples of thermal springs and geysers focused largely on the Upper Geyser Basin, but from other geothermal areas as well. Sr isotopes were also analyzed in samples of streamflow from several different areas in the Park as well as in samples of whole rock or mineral separates as a means of better defining sources of Sr that are incorporated into thermal water. Finally, authigenic mineral deposits precipitated from spring discharge inherit the Sr- and U-isotopic composition of the water from which they formed. Travertine precipitated from several areas in the Upper Geyser Basin were analyzed as a means of assessing their ages, determined by U-Th disequilibrium methods, and the Sr- and U-isotopic compositions of their source water at the time they formed.