Hydrologic landscape regions (HLRs) in the United States were delineated by using geographic information system (GIS) tools and statistical methods including principal components and cluster analyses. The GIS and statistical analyses were applied to land-surface form, geologic texture (permeability of the soil and bedrock), and climate variables that describe the physical and climatic setting of 43,931 small (roughly 200 square kilometers) watersheds in the United States. The analyses then grouped the watersheds into 20 noncontiguous regions (the HLRs) on the basis of similarities in land-surface form, geologic texture, and climate characteristics. This hydrologic landscape regions dataset contains for each of the 43,931 watersheds the (1) watershed identification number, (2) land-surface form, geologic texture, and climate characteristics for each watershed, and (3) hydrologic landscape region number for each watershed.

This point feature class contains 81,481 points arranged in a 270-meter spaced grid that covers the Spring Mountains and Sheep Range in Clark County, Nevada. Points are attributed with hydroclimate variables and ancillary data compiled to support efforts to characterize ecological zones.

The Great Basin is characterized by strong patterns of precipitation along approximate north-south gradients (Miller and others, 2013). Hence, we used a hydrographic boundary layer developed by Mason (1999), to divide the region-wide extent of sage-grouse habitat mapping analysis into North and South regions that align coarsely with respective mesic (wet) and xeric (dry) regions of the state. Flood regions are based largely on patterns of snowmelt, summer thunderstorms or cyclonic rainfall, and the 8-digit Watershed Boundary Dataset (WBD, 2015) was used to select appropriate watersheds within our mapping extent that corresponded to the Mason (1999) boundary. Slight adjustments, made in ArcMap 10.3, included joining region 2 and 3 to comprise the majority of the North region (where a relatively low number of sampled sites precluded keeping regions 2 and 3 separate), and pooling the more xeric Owyhee Desert (located in the center of the northern part of Nevada) within the drier South region. Use of the hydrographic boundary allowed for an accounting of broad-scale variation in habitat availability and selection patterns for sage-grouse (for example, habitat classified as highly suitable in wet areas could be classified as less suitable in drier areas because these habitats are less available). Interim statewide habitat suitability maps were clipped by the hydrographic boundary and relativized according to their respective maximum values for map classification purposes (see Coates and others 2014), the independent set of sage-grouse telemetry points was also split by the hydrographic boundary. For the spring map, 837 points informed the North region while 794 informed the South region. For the summer map, 604 points informed the North and 794 the South. For winter, 326 informed the North and 411 the South. For our composite annual map made from the multiplicative product of the seasonal maps, 1767 points were used for the North and 1999 for the South. References: Coates, P.S., Casazza, M.L., Brussee, B.E., Ricca, M.A., Gustafson, K.B., Overton, C.T., Sanchez-Chopitea, E., Kroger, T., Mauch, K., Niell, L., Howe, K., Gardner, S., Espinosa, S., and Delehanty, D.J. 2014, Spatially explicit modeling of greater sage-grouse (Centrocercus urophasianus) habitat in Nevada and northeastern California—A decision-support tool for management: U.S. Geological Survey Open-File Report 2014-1163, 83 p., http://dx.doi.org/10.3133/ofr20141163. ISSN 2331-1258 (online) Mason, R.R. 1999. The National Flood-Frequency Program—Methods For Estimating Flood Magnitude And Frequency In Rural Areas In Nevada U.S. Geological Survey Fact Sheet 123-98 September, 1999, Prepared by Robert R. Mason, Jr. and Kernell G. Ries III, of the U.S. Geological Survey; and Jeffrey N. King and Wilbert O. Thomas, Jr., of Michael Baker, Jr., Inc. http://pubs.usgs.gov/fs/fs-123-98/ Miller RF, Chambers JC, Pyke DA, Pierson FB, Williams CJ. 2013. A review of fire effects on vegetation and soils in the Great Basin Region: response and ecological site characteristics. Gen. Tech. Rep. RMRS-GTR-308. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. http://www.fs.fed.us/rm/pubs/rmrs_gtr308.html. WBD, 2015. Coordinated effort between the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS), the United States Geological Survey (USGS), and the Environmental Protection Agency (EPA). The Watershed Boundary Dataset (WBD) was created from a variety of sources from each state and aggregated into a standard national layer for use in strategic planning and accountability. Watershed Boundary Dataset for {HUC#8}, Nevada_ST.zip [ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Hydro/FileGDB101/]. Available URL: http://datagateway.nrcs.usda.gov [Accessed 01/10/2015].

This data release contains raster geospatial data for characterizing drainage basins in the Nevada StreamStats study area. Included are precipitation, temperature, elevation, slope, and land cover data.

This data set consists of sub delineations of the hydrographic area (HA) boundaries and polygons drawn at 1:1,000,000 scale for the Great Basin supplemented by information from HA drawn at 1:750,000 scale where necessary. See the process steps for more information.

This dataset consists of digitized 1:24,000-scale polylines and polygons representing hydrographic areas for the Walker River basin, California and Nevada.

This data set consists of hydrogeology for the State of Nevada. Consolidated rocks and unconsolidated sediments are the two major hydrogeologic units. Consolidated rocks are subdivided into 8 hydrogeologic units: (1) carbonate rocks, Quaternary to Tertiary-age; (2) basaltic, (3) rhyolitic, and (4) andesitic volcanic flows; (5) volcanic breccias, tuffs, and volcanic rocks older than Tertiary-age; (6) intrusive and metamorphic rocks; (7) consolidated and semi-consolidated tuffaceous rocks and sediments; and (8) clastic rocks consisting of sandstone and siltstone. Unconsolidated sediments are subdivided into 4 hydrogeologic units: 1) alluvial slopes, (2) valley floors, (3) fluvial deposits, and (4) playas. In addition, soil permeability is provided and grouped into five descriptive categories ranging from very high to very low, which generally correspond to mapped geomorphic features such as playas and alluvial slopes. The geologic map of Nevada (Stewart and Carlson, 1978), published at a scale of 1:500,000, is the primary source of lithology used to delineate hydrogeologic units, enhanced with elevation and hydrologic data, and supplemented with Landsat Thematic Mapper imagery (Maurer and others, 2004). Cited References Maurer, D.K., Lopes, T.J., Medina, R.L., and Smith, J.L., 2004, Hydrogeology and hydrologic landscape regions of Nevada, U.S. Geological Survey Scientific Investigations Report 2004-5131, 35 p. Stewart, J.H., and Carlson, J.E., 1978, Geologic map of Nevada: U.S. Geological Survey, prepared in cooperation with the Nevada Bureau of Mines and Geology, 1:500,000 scale, 2 sheets.

This U.S. Geological Survey data release contains data for Smith and Mason Valleys, California and Nevada, from the 2009 publication: Lopes, T.J.,and Allander, K.K., 2009, Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada: U.S. Geological Survey Scientific Investigations Report 2009–5155, https://doi.org/10.3133/sir20095155. Data include (1) 1:24,000-scale hydrographic areas, (2) selected well sites used to develop autumn 2006 groundwater-level contours, and (3) autumn 2006 groundwater-level contours. Since the publication of Lopes and Allander (2009), the positional coordinates and land-surface altitudes at selected well sites used to develop autumn 2006 groundwater-level contours in that report were updated as part of a 2022 U.S. Geological Survey study (Davies and Naranjo, 2022).

These data consist of species relative cover, percent cover of dead plant material, percent cover of soil and rock, and a variety of broad - and local- scale environmental variables. These data relate to sample sites along the Colorado River through Grand Canyon between Lees Ferry and river mile 245. The plant and ground cover data included here were originally collected as a part of annual vegetation monitoring by Grand Canyon Monitoring and Research Center. Environmental variables were either recorded in the field or obtained through other data sources. Species and ground cover data were collected in August and September 2014 at 96 randomly selected sample sites that were approximately evenly distributed along the river corridor. The sample sites were distributed among three geomorphic features: channel margins (44), debris fans (28), and sandbars (24).

This data release contains vector and raster geospatial data for delineating drainage basins in the Nevada StreamStats study area. Included are vector streamline, waterbody, and inner wall data used to hydrologically condition the digital elevation model. The hydrologically-conditioned digital elevation model, flow direction, flow accumulation, and stream delineation raster data are also included.