Water and gas chemistry data from: Benson, S.M., Janik, C.J., Long, D.C., Solbau, R.D. and Lienau, P.J., 1984. Data from pumping and injection tests and chemical sampling in the geothermal aquifer at Klamath Falls, Oregon: U.S. Geological Survey Open File Report 84-146, 114 p., https://doi.org/10.3133/ofr84146. Water chemistry data was digitized for 18 samples. Reported attributes include: Sample name, Type, Collection date, Reported location, State, County, Latitude, Longitude, Location resolution, Well depth, Temperature, pH (field), pH (lab), Aluminum (Al), Calcium (Ca), Chloride (Cl), Fluoride (F), Bicarbonate (HCO3), Mercury (Hg), Potassium (K), Lithium (Li), Sodium (Na), Silica (SiO2), Sulfate (SO4), Reported cations, Reported anions, Cations, Anions, Salinity, Delta 2H, Delta 18O (H2O), Delta 18O (SO4), Tritium (3H), Digitizer comment. Gas chemistry data was digitized for 18 samples. Reported attributes include: Sample name, Type, Collection date, Reported location, State, County, Latitude, Longitude, Location resolution, Temperature, Dissolved carbon dioxide (CO2 dissolved), Isotopic composition of carbon in carbon dioxide (Delta 13C CO2). Data was digitized from Tables 4, 5, and 6. The following tables were not digitized: Table 1 (2-1): data from a seven-week aquifer (pumping) and re-injection test. Table 2 (2-2): roughly 24 hours of pressure-falloff data beginning immediately after the aquifer test pumping stopped (i.e., shut in). Table 3 (2-3): physical data from wells monitored for the aquifer test. Table 7 (5-1): monthly mean air temperatures and estimated average monthly thermal discharge calculated from air temperature.