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In the summers of 2004, 2005, 2006, and 2008 the U.S. Geological Survey conducted a reconnaissance geochemical survey of the drainage basins throughout Taylor Mountains 1:250,000-scale quadrangle, in southwestern Alaska. The purpose of the study was to locate areas of potential interest for ore minerals, provide data that may be used to determine regional-scale element baselines, and provide data for the concurrent U.S. Geological Survey geologic mapping and mineral resource assessment effort. This report provides the stream-sediment sample data for the study. Introduction During the summers of 2004, 2005, 2006, and 2008 the U.S. Geological Survey (USGS) conducted a reconnaissance geochemical survey of the drainage basins throughout the Taylor Mountains 1:250,000-scale quadrangle of Alaska. The purpose of this study was to locate areas of potential interest for ore minerals, provide data that may be used to determine regional-scale element baselines, and provide data for the concurrent USGS geologic mapping and mineral resource assessment effort. This report provides the stream-sediment sample data for the study (tables 1-3). The Taylor Mountains quadrangle, which covers approximately 6,700 mi 2 , is located in southwestern Alaska (fig.1). There are no towns or villages in the quadrangle; access to the study area is limited to air travel. Topographic relief ranges from near sea level to a maximum of about 3,500 ft at Taylor Mountain. Much of the topography of the region consists of low, rolling mountains. Where present, outcrops consist mostly of eroded bedrock and rubble. Boreal forests dominate the region, grading from white spruce, birch, and trembling aspen on uplands to black spruce and tamarack in lowlands. Tall willow, birch, and alder shrub communities are scattered throughout the region (Nowacki and others, 2001). Several mineral prospects have been noted in the Taylor Mountains quadrangle (Hudson, 2001) and there is small-scale gold placer activity at the Taylor Mountains mine. Additional geochemical data for rock and stream-water samples collected as part of this project are available in Klimasauskas and others, 2006a, Klimasauskas and others, 2006b, Klimasauskas and others, 2007, Wang and others, 2006a, and Wang and others, 2006b. Two additional reports by Wang and others containing analytical data for stream-water samples collected in 2006 and in 2008 are in review.

We report on the chemical analysis of water samples collected from the Taylor Mountains 1:250,000-scale quadrangle. Parameters for which data are reported include pH, conductivity, water temperature, major cation and anion concentrations, trace-element concentrations, and dissolved organic-carbon concentrations. Samples were collected as part of a multiyear U.S. Geological Survey project “Geologic and Mineral Deposit Data for Alaskan Economic Development.” Data presented here are from samples collected in June and July of 2005. The data are being released at this time with minimal interpretation. This is the second release of aqueous geochemical data from this project; 2004 aqueous geochemical data were published previously (Wang and others, 2006). The data in this report augment but do not duplicate or supersede the previous data release. Site selection was based on a regional sampling strategy that focused on firstand second-order drainages. Water sample site selection was based on landscape parameters that included physiography, wetland extent, lithological changes, and a cursory field review of mineralogy from pan concentrates. Stream water in the Taylor Mountians quadrangle is dominated by bicarbonate (HCO3-), though in a few samples more than 50 percent of the anionic charge can be attributed to sulfate ( SO42-). The major-cation chemistry ranges from Ca2+/Mg2+ dominated to a mix of Ca2+/Mg2+/Na++K+. In general, good agreement was found between the major cations and anions in the duplicate samples. Many trace elements in these samples were at or near the analytical method detection limit, but good agreement was found between duplicate samples for elements with detectable concentrations. With the exception of a total mercury concentration of 0.33 ng/L detected in a field blank, field blank major-ion and trace-elements concentrations were below detection.