The U.S. Geological Survey (USGS), in cooperation with the Bureau of Reclamation, began hydrogeologic investigations in 2009 in the Paradox Valley in Colorado. In June 2011, nine groundwater samples were collected from selected wells and springs in the study area. The samples were analyzed for a suite of environmental tracers and dissolved gases that were used to model recharge temperatures and groundwater ages. All geochemical and environmental tracer results used in the models are available in the USGS National Water Information System (NWIS) using USGS station numbers. This data release presents the data and modeling results in four CSV files. The file C14_age_models.csv presents laboratory results for carbon-14 (14C) and carbon-13 (13C) for each sample, the unadjusted 14C ages provided by the laboratory, and groundwater ages estimated the Tamers and Pearson models. The file Tritium_data.csv includes the results of the tritium analysis and the file NobleGas_data.csv includes noble gas concentrations and inputs for the modeling. The file ParadoxTracerModeling.csv contains the model results for noble gas recharge temperatures and Hydrogen-3/Helium-3 groundwater ages.