Bathymetric, topographic, and grain-size data were collected in April 2011 along a 27-mi (43.5 – km) reach of the Colorado River in Grand Canyon National Park, Arizona. The study reach begins at river mile 61.1, about 0.6 -mi (1 –km) above the confluence of the Colorado and Little Colorado Rivers and ends at river mile 88.1 at the upstream boundary of the Bright Angel Rapid (Phantom Ranch boat beach). Channel bathymetry was mapped using multibeam and singlebeam echosounders, subaerial topography was mapped using ground-based total-stations, and bed-sediment grain-size data were collected using an underwater digital microscope system. These data were combined to produce digital elevation models, spatially variable estimates of digital elevation model uncertainty, georeferenced grain-size data, and bed-sediment distribution maps. These data were collected by the Southwest Biological Science Center, Grand Canyon Monitoring and Science Center as a component of a larger effort to monitor the status and trends of sand storage along the Colorado River in Grand Canyon National Park. This dataset is a 1-meter resolution digital elevation model.

Bathymetric, topographic, and grain-size data were collected in April 2011 along a 27-mi (43.5 – km) reach of the Colorado River in Grand Canyon National Park, Arizona. The study reach begins at river mile 61.1, about 0.6 -mi (1 –km) above the confluence of the Colorado and Little Colorado Rivers and ends at river mile 88.1 at the upstream boundary of the Bright Angel Rapid (Phantom Ranch boat beach). Channel bathymetry was mapped using multibeam and singlebeam echosounders, subaerial topography was mapped using ground-based total-stations, and bed-sediment grain-size data were collected using an underwater digital microscope system. These data were combined to produce digital elevation models, spatially variable estimates of digital elevation model uncertainty, georeferenced grain-size data, and bed-sediment distribution maps. These data were created by the Southwest Biological Science Center, Grand Canyon Monitoring and Science Center as a component of a larger effort to monitor the status and trends of sand storage along the Colorado River in Grand Canyon National Park. This dataset is the hillshade generated from the 1-meter resolution digital elevation model (DEM_EGC_Apr2011.tif) associated with this data release.

Bathymetric, topographic, and grain-size data were collected in April 2011 along a 27-mi (43.5 – km) reach of the Colorado River in Grand Canyon National Park, Arizona. The study reach begins at river mile 61.1, about 0.6 -mi (1 –km) above the confluence of the Colorado and Little Colorado Rivers and ends at river mile 88.1 at the upstream boundary of the Bright Angel Rapid (Phantom Ranch boat beach). Channel bathymetry was mapped using multibeam and singlebeam echosounders, subaerial topography was mapped using ground-based total-stations, and bed-sediment grain-size data were collected using an underwater digital microscope system. These data were combined to produce digital elevation models, spatially variable estimates of digital elevation model uncertainty, georeferenced grain-size data, and bed-sediment distribution maps. These data were created by the Southwest Biological Science Center, Grand Canyon Monitoring and Science Center as a component of a larger effort to monitor the status and trends of sand storage along the Colorado River in Grand Canyon National Park. This dataset is a 1-meter resolution elevation uncertainty model generated by fuzzy inference system modeling associated from the 1-meter resolution digital elevation model (DEM_EGC_Apr2011.tif) associated with this data release.

These topographic/bathymetric digital elevation models (DEMs) were collected and compiled to characterize erosion and deposition in the Colorado River and in an adjacent zone of laterally recirculating flow (eddy) during both average flow conditions and during a controlled flood that occurred in March 2008. The objectives of the study were to measure changes sandbar morphology that occurred during changes in discharge associated with the controlled flood. These data were collected between February 6 and March 31, 2008 in a 1-mile study reach on the Colorado River within Grand Canyon National Park beginning 44.5 miles downstream from Lees Ferry, Arizona. These data were collected by the USGS Grand Canyon Monitoring and Research Center with cooperators from Northern Arizona University and funding provided by the Glen Canyon Dam Adaptive Management Program. All bathymetric data were collected with a multibeam sonar system (Reson Seabat 8124 sonar with TSS MAHRSS reference system for heave, pitch, roll, and heading). Topographic data were collected by conventional total station. These data can be used to study changes in channel morphology associated with changes in streamflow conditions.

These data were compiled to visualize the extent of Lake Powell at various elevation levels. These data represent water surface elevations for Lake Powell at levels critical to the operation of Glen Canyon Dam, at 5 foot intervals from the "Equalization Tier" ("Full Pool") to "Dead Pool", and at maximum and minimum elevations each water year throughout Glen Canyon Dam's operating history. These data were created for Lake Powell in Arizona and Utah. These data were created by the U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring & Research Center by reclassifying "Modified topobathymetric elevation data for Lake Powell" (Jones and Root, 2021) at discrete elevation levels and converting them into vector format. These data can be used to visualize locations or resources in Lake Powell at various elevation levels as it continues to change.

These profiles of suspended-sediment concentration were collected and compiled to characterize suspended sediment in the Colorado River during both average flow conditions and during a controlled flood that occurred in March 2008. The objectives of the study were to measure changes in suspended sediment that occurred during changes in discharge associated with the controlled flood. These data were collected between March 4 and March 10, 2008 in the center of the channel 44.64 river miles downstream from Lees Ferry, Arizona on the Colorado River within Grand Canyon National Park. The sampling location was within a 1-mile study reach beginning 0.14 miles upstream from the sampling location. These data were collected by the USGS Grand Canyon Monitoring and Research Center with cooperators from Northern Arizona University and funding provided by the Glen Canyon Dam Adaptive Management Program. All samples were collected with USGS P-61 point integrating sampler. Samples were processed for silt and clay concentration, sand concentration, and sand grain size using standard methods. These data can be used to study suspended sediment concentration, which can be used in predictions of sediment transport and can be used to develop, calibrate, and verify transport models.

To support the modeling of the Colorado River water storage area capacity tables by the U.S. Geological Survey (USGS) Utah Water Science Center in the Glen Canyon National Recreation Area in Utah and Arizona, the USGS Earth Resources Observation and Science (EROS) Center has created an integrated 1-meter topobathymetric digital elevation model (TBDEM) for Lake Powell, the second largest man-made reservoir in the United States. Located in south-central Utah and north-central Arizona, Lake Powell is a reservoir on the Colorado River created by the flooding of a natural canyon by the construction of Glen Canyon Dam. The new Lake Powell TBDEM consists of the best available multi-source topographic and bathymetric elevation data for Lake Powell onshore and offshore areas. The Lake Powell TBDEM integrates three different data sources including topographic light detection and ranging (lidar) point cloud data, multibeam bathymetric surveys, and historic topographic surveys obtained from the Department of the Interior (DOI) Bureau of Reclamation (BOR) and USGS Woods Hole Coastal Marine Science Center. The topographic, bathymetric, and historic topographic surveys were sorted and prioritized based on survey date, accuracy, spatial distribution, and point density to develop a TBDEM model based on the best available elevation data. The Lake Powell TBDEM spatial resolution is 1-meter with the general location ranging from Glen Canyon Dam northwest of Page, Arizona to White Canyon, Utah with elevations from 948.28 meters to 1440.94 meters referenced to North American Vertical Datum of 1988 (NAVD88), National Geodetic Survey Geoid 12B. The topographic lidar survey was acquired from 4/2/18 to 4/3/18. The bathymetry survey was acquired from 10/8/17 to 11/15/17. The historic topographic surveys ranged from 1947-1959. Some of the nearshore void zone (not covered by lidar or multibeam) was filled with historic topographic surveys digitized from historical maps from 1947-1959 and a kriging interpolation as published by the USGS Coastal National Elevation Database (CoNED) Applications Project at https://doi.org/10.2112/SI76-008. Additional information regarding the CoNED Applications Project is located at https://www.usgs.gov/land-resources/eros/coned.

This part of DS 781 presents data for the bathymetry map of the Hueneme Canyon and Vicinity map area, California. The raster data file for the bathymetry map is included in "Bathymetry_HuenemeCanyon.zip," which is accessible from https://pubs.usgs.gov/ds/781/HuenemeCanyon/data_catalog_HuenemeCanyon.html. These data accompany the pamphlet and map sheets of Johnson, S.Y., Dartnell, P., Cochrane, G.R., Golden, N.E., Phillips, E.L., Ritchie, A.C., Kvitek, R.G., Greene, H.G., Krigsman, L.M., Endris, C.A., Clahan, K.B., Sliter, R.W., Wong, F.L., Yoklavich, M.M., and Normark, W.R. (S.Y. Johnson, ed.), 2012, California State Waters Map Series—-Hueneme Canyon and Vicinity, California: U.S. Geological Survey Scientific Investigations Map 3225, 41 p., 12 sheets, scale 1:24,000, https://pubs.usgs.gov/sim/3225/. The bathymetry map of the Hueneme Canyon and Vicinity map area, California, was generated from bathymetry data collected by California State University, Monterey Bay (CSUMB), by the U.S. Geological Survey (USGS), and by Fugro Pelagos for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise. Most of the offshore area was mapped by CSUMB in the summers of 2006 and 2007, using a 244-kHz Reson 8101 multibeam echosounder. The far northern part of the offshore area was mapped by the USGS in 2006, using a 117-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. The nearshore bathymetry and coastal topography were mapped for USACE by Fugro Pelagos in 2009, using the SHOALS-1000T bathymetric-lidar and Leica ALS60 topographic-lidar systems. These mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters.

This portion of the data release presents a digital elevation model (DEM) of portions of Oxbow Reservoir in Placer County, California. The DEM was created using topographic survey data collected on 26 October 2022, when the reservoir was partially de-watered to allow repairs to the dam infrastructure following the Mosquito Fire. Although the gates of the dam were open during this time, significant portions of the reservoir site remained inaccessible to surveyors due to the continued flow of the Middle Fork American River. Consequently, this DEM covers approximately 50 percent of the total surface area of the reservoir at full pool. The raw topographic data for the DEM were collected using two RTK GNSS backpack rovers which were referenced to a temporary GNSS base station occupying a fixed control point ("CP512") located less than 1 kilometer from the survey area. Precise coordinates for the GNSS base station were derived using the National Geodetic Survey (NGS) Online Positioning User Service (OPUS). The GNSS data were used to create a triangulated irregular network (TIN), which was converted to raster DEM. The resulting DEM has a horizontal resolution of 1 meter and is formatted as a GeoTIFF.