[en] This data report presents results of ground water and stream sediment reconnaissance in the National Topographic Map Series (NTMS) Walker Lake 1⁰ x 2⁰ quadrangle. Surface sediment samples were collected at 797 sites or at a nominal density of one site per 20 square kilometers (eight square miles). Ground water samples were collected at 77 sites or at a nominal density of one site per 220 square kilometers (87 square miles). Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 8 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included. Data from ground water sites (on microfiche in pocket) include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements (water temperature, well description, and scintillometer reading), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, He, Mg, Mn, Na, and V). Data from sediment sites (also on microfiche in pocket) include (1) water chemistry measurements (pH, conductivity, and alkalinity), and (2) elemental analyses (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulatedn Symbol plot maps, histograms, and cumulative frequency plots for most elements, U/Th and U/Hf ratios, and scintillometer readings are included on the microfiche