This data release consists of three child items distinguishing the following types of data: light detection and ranging (lidar) point clouds (LPCs), digital elevation models (DEMs), and snow depth raster maps. These three data types are all derived from lidar data collected on small, uncrewed aircraft systems (sUAS) at study areas in the Upper Colorado River Basin, Colorado, from 2020 to 2022. These data were collected and generated as part of the U.S. Geological Survey's (USGS) Next Generation Water Observing Systems (NGWOS) Upper Colorado River Basin project.

The U.S. Geological Survey contracted with Juniper Unmanned to conduct field tests of the ASTRALiTe bathymetric lidar system upstream and downstream of its confluence with the Blue River near Kremmling, Colorado, on October 18, 2018. The objective of this project was to assess the potential to map river bathymetry (i.e., channel bed topography) using lidar data collected from an unmanned aircraft system (UAS). The ASTRALiTe lidar instrument was mounted on a DJI Matrice 600 Pro UAS owned and operated by Juniper Unmanned. As part of the study, Juniper's pilot flew the ASTRALiTe instrument across 2 river transects (cross-stream) on the Blue River and 2 river transects on the Colorado River. This data release includes data delivered to the USGS by ASTRALite on November 15, 2018. The data have been parsed into separate text files for bare earth (i.e., river bed) and water surface returns for each cross-section but have not been filtered or modified in any other way.

The U.S. Geological Survey contracted with LiteWave Technologies (formerly ASTRALiTe) to fly their production topo-bathymetric lidar system (Edge) along the Colorado River near McCoy, Colorado, on September 8-9, 2021. The objective of this project was to assess the potential to map river bathymetry (i.e., river-bed topography) using lidar data collected from an uncrewed aircraft system (UAS). The Edge was mounted on a UAS owned and operated by LiteWave Technologies. This data release includes data delivered to the USGS by LiteWave Technologies on November 9, 2021. Grid coordinates are projected in Universal Transverse Mercator Zone 13 North and are represented in units of meters. The topo-bathymetric elevations, in units of meters, delivered by the contractor are believed to be relative to the height of the GRS80 ellipsoid and differ from the more commonly used orthometric height computed by the addition of the geoid height to the GRS80 ellipsoid. The data is provided as a LAS file which includes points classified as bathymetric or river bottom (code 40), created, never classified (code 0), and water surface returns (code 41). These data delivered to USGS have not been filtered or modified.

2010 Boulder Creek, Colorado Snow-Off LiDAR Surveys LiDAR was acquired for a 600 km2 area inside the Boulder Creek watershed during a snow-off (August, 2010) time slice, near Boulder Colorado. This data was collected in collaboration between the National Center for Airborne Laser Mapping (NCALM) project and the Boulder Creek Critical Zone Observatory (CZO), both funded by the National Science Foundation (NSF). The dataset contains 1 m Digital Surface Models (first-stop), Digital Terrain Models (bare-earth), and 10 points/m2 LAS-formated point cloud tiles. The DSMs and DTMs are available in GeoTIFF format, approx. 1-2 GB each, with associated shaded relief models, for a total of 15 GB of data. The Digital Terrain Model (DTM) is a ground-surface elevation dataset better suited for derived layers such as slope angle, aspect, and contours. Accessory layers consist of index map layers for point cloud tiles, DEM extent, and flight lines. Other LiDAR DSMs, DTMs, and point cloud data available in this series include snow-on data for 2010. Together, the LiDAR Digital Elevation Models (DEM) and point cloud data will be of interest to land managers, scientists, and others for study of topography, snow, ecosystems and environmental change. The Boulder Creek CZO will be using the LiDAR data to further their mission of focusing on how water, atmosphere, ecosystems, & soils interact and shape the Earth's surface. The "Critical Zone" lies between rock and sky. It is essential to life - including human food production - and helps drive Earth's carbon cycle, climate change, stream runoff, and water quality. PLEASE READ the FGDC-compliant metadata files that are available for each dataset (in .html, .txt, and .xml formats). These files provide numerous details that may be of interest. Also included are flight lines, survey reports, reference materials, and DEM extent shapefiles. Publications associated with this dataset can be found at NCALM's Data Tracking Center

ArcGIS API application that shows study site extents, sampling and sensor locations, LIDAR, glacier extents, aerial imagery extents with downloads.

Please use the links below https://bcczo.colorado.edu/gisarc/arcapi.html

For more in-depth Lidar visit our friends at OpenTopgraphy and click http://criticalzone.org/boulder/data/dataset/2921/ HERE They are large storage for all our Lidar data.

There is a Boulder County focus inherited from the Boulder Creek Critical Zone program. If you are aware of a resource worth sharing please let us know. Files are in the versatile KML format for ease of sharing. If you have trouble importing these into ArcGIS or another program just let us know.

SITE EXTENTS: Kml's that shows study site extents. The main set of extents was created by Kyotaek Hwang.

SITE: BOULDER CREEK BOULDER COUNTY More Boulder County data can be found here: https://opendata-bouldercounty.hub.arcgis.com/ Selected kmls include: - Archaeologically_Sensitive_Areas - County_Open_Space - Lakes_and_Reservoirs (included modern glaciers) - mun_wtrsheds_czo (restricted areas) - Open_space_czo - Riparian_Areas_-_2013_ERE - Road_Map_Roads

GEOLOGY - Geological map by Ogden Tweto, clipped here to Boulder Creek, geo_czo_tweto https://coloradogeologicalsurvey.org/publications/tweto-geologic-map-colorado-1979/

• Clipped Cole & Braddock geologic map

SOILS Natural Resources Conservation Service soil maps https://www.nrcs.usda.gov - soilmu_a_co643_bc (boulder County) - soilmu_a_co645_arnf (Arapaho National Forest

GLACIERS Madole's Glaciers LGM. No online source. Check licensing before using in publication

TOPOGRAPHIC Topographic Lines created but the BcCZO from 30m USGS DEM

LIDAR For Lidar: OpenTopgraphy 2010 Lidar, Snow ON Snow Off https://portal.opentopography.org/dataSearch?search=Boulder%20creek%20CZO

SITE: COAL CREEK Coal Creek Trails

The U.S. Geological Survey contracted with Juniper Unmanned to conduct field tests of the ASTRALiTe bathymetric lidar system on the Blue River just upstream of its confluence with the Colorado River near Kremmling, Colorado, on October 18, 2018. The objective of this project was to assess the potential to map river bathymetry (i.e., channel bed topography) using lidar data collected from an unmanned aircraft system (UAS). The ASTRALiTe lidar instrument was mounted on a DJI Matrice 600 Pro UAS owned and operated by Juniper Unmanned. As part of the study, Juniper's pilot flew the ASTRALiTe instrument across 2 river transects (cross-stream) on the Blue River. This data release includes data delivered to the USGS by ASTRALite on November 15, 2018. The data have been parsed into separate text files for bare earth (i.e., river bed) and water surface returns for each cross-section but have not been filtered or modified in any other way.

This 1m Digital Terrain Model (DTM) is a snow-off DTM derived from bare-ground Light Detection and Ranging (LiDAR) point cloud data from August 2010 for the Boulder Creek Critical Zone Observatory (CZO), near Boulder Colorado. This dataset is better suited for derived layers such as slope angle, aspect, and contours. The DTM was created from 1,375 LiDAR point cloud tiles subsampled from 10 points/m2 to 1-meter postings, acquired by the National Center for Airborne Laser Mapping (NCALM) project. This data was collected in collaboration between the Boulder Creek CZO and NCALM, both funded by the National Science Foundation (NSF). The DTM has the functionality of a map layer for use in Geographic Information Systems (GIS) or remote sensing software. Total area imaged is 598.92 km^2. The LiDAR point cloud data was acquired with an Optech Gemini Airborne Laser Terrain Mapper (ALTM) and mounted in a Piper Twin PA-31 Chieftain with Inertial Measurement Unit (IMU) at a flying height of 600 m. Data from four GPS (Global Positioning System) ground stations were used for aircraft trajectory determination. The continuous DTM surface was created by mosaicing and then kriging 0.5 x 1 km LiDAR point cloud LAS-formated tiles using Golden Software's Surfer 8 Kriging algorithm. Horizontal accuracy is at least, but usually better than, 11 cm RMSE at 1 sigma and vertical accuracy is 5-30 cm RMSE at 1 sigma. The layer is available in IMAGINE format approx. 4 GB of data. It has a UTM zone 13 projection, with a NAD83 horizonal datum and a NAVD88 vertical datum, with FGDC-compliant metadata. A shaded relief model was also generated. A similar layer, the Digital Surface Model (DSM), is a first-stop elevation layer. Accessory layers consist of index map layers for point cloud tiles and flight lines, each with detailed attribute information such as acquisition date and tile file name. The DTM is available through an unrestricted public license. Other LiDAR DSMs, DTMs, and point cloud data available in this series include snow-on data for 2010. Together, the LiDAR DEMs and point cloud data will be of interest to land managers, scientists, and others for study of topography, snow, ecosystems, and environmental change. NOTE: This EML metadata file does not contain important geospatial data processing information. Before using any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC compliant format, using ArcGIS software (ArcCatalog > description), or by viewing the .xml file provided with the geospatial dataset.

Airborne LiDAR data were acquired over the East River Watershed on June 8, 2015 to August 10, 2015. The area covered was approximately 4933 square kilometers with an average point density of 10-12 points per square meter to comply with USGS's QL1 standard. Additional products include the LiDAR point cloud and derived products (including the digital elevation map, top-of-canopy elevation). The attached LIDAR acquisition report accompanies the delivered LiDAR data and documents contract specifications, data acquisition procedures, acquisition parameters (e.g., flight line trajectories, coverage maps), processing methods, and analysis of the final dataset including LiDAR accuracy and density. The metadata can be accessed by using GIS software (QGIS, ArcGIS) or remote sensing software (ENVI). The LiDAR data collection was funded by the Watershed Function SFA project and IDEAS-Watersheds projects supported by U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research under award no. DE-AC02-05CH11231.

This 1m Digital Surface Model (DSM) shaded relief is derived from first-stop Light Detection and Ranging (LiDAR) point cloud data from September 2005 for the Green Lakes Valley, near Boulder Colorado. The DSM was created from LiDAR point cloud tiles subsampled to 1-meter postings, acquired by the National Center for Airborne Laser Mapping (NCALM) project. This data was collected in collaboration between the University of Colorado, Institute of Arctic and Alpine Research (INSTAAR) and NCALM, which is funded by the National Science Foundation (NSF). The DSM shaded relief has the functionality of a map layer for use in Geographic Information Systems (GIS) or remote sensing software. Total area imaged is 35 km^2. The LiDAR point cloud data was acquired with an Optech 1233 Airborne Laser Terrain Mapper (ALTM) and mounted in a twin engine Piper Chieftain (N931SA) with Inertial Measurement Unit (IMU) at a flying height of 600 m. Data from two GPS (Global Positioning System) ground stations were used for aircraft trajectory determination. The continuous DSM surface was created by mosaicing and then kriging 1 km2 LiDAR point cloud LAS-formated tiles using Golden Software's Surfer 8 Kriging algorithm. Horizontal accuracy and vertical accuracy is unknown. cm RMSE at 1 sigma. The layer is available in GEOTIF format approx. 265 MB of data. It has a UTM zone 13 projection, with a NAD83 horizonal datum and a NAVD88 vertical datum computed using NGS GEOID03 model, with FGDC-compliant metadata. This shaded relief model was also generated. A similar layer, the Digital Terrain Model (DTM), is a ground-surface elevation dataset better suited for derived layers such as slope angle, aspect, and contours. A processing report and readme file are included with this data release. The DSM dataset is available through an unrestricted public license. The LiDAR DEMs will be of interest to land managers, scientists, and others for study of topography, ecosystems, and environmental change. NOTE: This EML metadata file does not contain important geospatial data processing information. Before using any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC compliant format, using ArcGIS software (ArcCatalog > description), or by viewing the .xml file provided with the geospatial dataset.

These snow depth raster maps were generated from digital elevation models (DEMs) derived from light detection and ranging (lidar) data collected during multiple field campaigns in the three study areas near Winter Park, Colorado. Small, uncrewed aircraft systems (sUAS) collected lidar datasets to represent snow-covered and snow-free periods. More information regarding the sUAS used and data collection methods can be found in the Supplemental Information and process step sections of each study area individual metadata file.

This 1m Digital Surface Model (DSM) is derived from first-stop Light Detection and Ranging (LiDAR) point cloud data from September 2005 for the Green Lakes Valley, near Boulder Colorado. The DSM was created from LiDAR point cloud tiles subsampled to 1-meter postings, acquired by the National Center for Airborne Laser Mapping (NCALM) project. This data was collected in collaboration between the University of Colorado, Institute of Arctic and Alpine Research (INSTAAR) and NCALM, which is funded by the National Science Foundation (NSF). The DSM has the functionality of a map layer for use in Geographic Information Systems (GIS) or remote sensing software. Total area imaged is 35 km^2. The LiDAR point cloud data was acquired with an Optech 1233 Airborne Laser Terrain Mapper (ALTM) and mounted in a twin engine Piper Chieftain (N931SA) with Inertial Measurement Unit (IMU) at a flying height of 600 m. Data from two GPS (Global Positioning System) ground stations were used for aircraft trajectory determination. The continuous DSM surface was created by mosaicing and then kriging 1 km2 LiDAR point cloud LAS-formated tiles using Golden Software's Surfer 8 Kriging algorithm. Horizontal accuracy and vertical accuracy is unknown. cm RMSE at 1 sigma. The layer is available in GEOTIF format approx. 265 MB of data. It has a UTM zone 13 projection, with a NAD83 horizonal datum and a NAVD88 vertical datum computed using NGS GEOID03 model, with FGDC-compliant metadata. A shaded relief model was also generated. A similar layer, the Digital Terrain Model (DTM), is a ground-surface elevation dataset better suited for derived layers such as slope angle, aspect, and contours. A processing report and readme file are included with this data release. The DSM is available through an unrestricted public license. The LiDAR DEMs will be of interest to land managers, scientists, and others for study of topography, ecosystems, and environmental change. NOTE: This EML metadata file does not contain important geospatial data processing information. Before using any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC compliant format, using ArcGIS software (ArcCatalog > description), or by viewing the .xml file provided with the geospatial dataset.

This 1m Digital Terrain Model (DTM) shaded relief is a snow-off DTM derived from bare-ground Light Detection and Ranging (LiDAR) point cloud data from August 2010 for the Boulder Creek Critical Zone Observatory (CZO), near Boulder Colorado. This dataset is better suited for derived layers such as slope angle, aspect, and contours. The DTM was created from 1,375 LiDAR point cloud tiles subsampled from 10 points/m2 to 1-meter postings, acquired by the National Center for Airborne Laser Mapping (NCALM) project. This data was collected in collaboration between the Boulder Creek CZO and NCALM, both funded by the National Science Foundation (NSF). The DTM has the functionality of a map layer for use in Geographic Information Systems (GIS) or remote sensing software. Total area imaged is 598.92 km^2. The LiDAR point cloud data was acquired with an Optech Gemini Airborne Laser Terrain Mapper (ALTM) and mounted in a Piper Twin PA-31 Chieftain with Inertial Measurement Unit (IMU) at a flying height of 600 m. Data from four GPS (Global Positioning System) ground stations were used for aircraft trajectory determination. The continuous DTM surface was created by mosaicing and then kriging 0.5 x 1 km LiDAR point cloud LAS-formated tiles using Golden Software's Surfer 8 Kriging algorithm. Horizontal accuracy is at least, but usually better than, 11 cm RMSE at 1 sigma and vertical accuracy is 5-30 cm RMSE at 1 sigma. The layer is available in IMAGINE format approx. 4 GB of data. It has a UTM zone 13 projection, with a NAD83 horizonal datum and a NAVD88 vertical datum, with FGDC-compliant metadata. A shaded relief model was also generated. A similar layer, the Digital Surface Model (DSM), is a first-stop elevation layer. Accessory layers consist of index map layers for point cloud tiles and flight lines, each with detailed attribute information such as acquisition date and tile file name. The DTM is available through an unrestricted public license. Other LiDAR DSMs, DTMs, and point cloud data available in this series include snow-on data for 2010. Together, the LiDAR DEMs and point cloud data will be of interest to land managers, scientists, and others for study of topography, snow, ecosystems, and environmental change. NOTE: This EML metadata file does not contain important geospatial data processing information. Before using any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC compliant format, using ArcGIS software (ArcCatalog > description), or by viewing the .xml file provided with the geospatial dataset.

Processed LiDAR data and environmental covariates from 2015 and 2019 LiDAR scans in the Vicinity of Snodgrass Mountain (Western Colorado, USA), in a geographic subset used in primary analysis for the research paper. This package contains LiDAR-derived canopy height maps for 2015 and 2019, crown polygons derived from the height maps using a segmentation algorithm, and environmental covariates supporting the model of forest growth. Source datasets include August 2015 and August 2019 discrete-return LiDAR point clouds collected by Quantum Geospatial for terrain mapping purposes on behalf of the Colorado Hazard Mapping Program and the Colorado Water Conservation Board. Both datasets adhere to the USGS QL2 quality standard. The point cloud data were processed using the R package lidR to generate a canopy height model representing maximum vegetation height above the ground surface, using a pit-free algorithm. This dataset was compiled to assess how spatial patterns of tree growth in montane and subalpine forests are influenced by water and energy availability. Understanding these growth patterns can provide insight into forest dynamics in the Southern Rocky Mountains under changing climatic conditions. This dataset contains .tif, .csv, and .txt files. This dataset additionally includes a file-level metadata (flmd.csv) file that lists each file contained in the dataset with associated metadata; and a data dictionary (dd.csv) file that contains column/row headers used throughout the files along with a definition, units, and data type.

LiDAR was acquired for a 600 km2 area inside the Boulder Creek watershed during a snow-off (August, 2010) time slice, near Boulder Colorado. This data was collected in collaboration between the National Center for Airborne Laser Mapping (NCALM) project and the Boulder Creek Critical Zone Observatory (CZO), both funded by the National Science Foundation (NSF). The dataset contains 1 m Digital Surface Models (first-stop), Digital Terrain Models (bare-earth), and 10 points/m2 LAS-formated point cloud tiles. The DSMs and DTMs are available in GeoTIFF format, approx. 1-2 GB each, with associated shaded relief models, for a total of 15 GB of data. The Digital Terrain Model (DTM) is a ground-surface elevation dataset better suited for derived layers such as slope angle, aspect, and contours. Accessory layers consist of index map layers for point cloud tiles, DEM extent, and flight lines. Other LiDAR DSMs, DTMs, and point cloud data available in this series include snow-on data for 2010.

This data set contains rasterized snow depth maps derived from lidar point cloud data collected from Grand Mesa, Colorado during the SnowEx20 campaign. The subset data file was used as input data to derive SWE and snow density data, which is available as SnowEx20 Grand Mesa IOP Lidar and GPR-Derived Snow Water Equivalent and Snow Density, Version 1.

This package is part of the Watershed Function SFA project and contains a remote sensing dataset acquired at the East River, Colorado. The remote sensing dataset is composed of vegetation maps computed from hyperspectral and LiDAR airborne data acquired by the NEON team in June 2018. The maps show the spatial distribution of plant species among trees, shrubs, and meadows at 1-meter resolution, covering four main catchments located in the Upper Colorado River Basin: the East River (67.5 km2), Washington Gulch (93.0 km2), Oh-be-Joyful Creek-Slate River (86.9 km2), and Coal Creek (53.2 km2). The maps were obtained through a supervised classification approach based on the support vector machine learning algorithm. The data input to the algorithm is the hyperspectral and LiDAR dataset. As pre-processing, an NDVI-based threshold was applied to mask bare soil, man-made structures, water, and shadows. The classification algorithm was applied following a hierarchical strategy. In the first step, the tree species were estimated. The algorithm was then applied to the remaining areas for the identification of shrubs and meadow plants. The various estimations were then merged to provide the final vegetation map. Some of the files are geotiffs, which require GIS software to visualize. jpeg files are extracted geotiffs.

This is a tiled collection of the 3D Elevation Program (3DEP) and is one meter resolution. The 3DEP data holdings serve as the elevation layer of The National Map, and provide foundational elevation information for earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. The elevations in this DEM represent the topographic bare-earth surface. USGS standard one-meter DEMs are produced exclusively from high resolution light detection and ranging (lidar) source data of one-meter or higher resolution. One-meter DEM surfaces are seamless within collection projects, but, not necessarily seamless across projects. The spatial reference used for tiles of the one-meter DEM within the conterminous United States (CONUS) is Universal Transverse Mercator (UTM) in units of meters, and in conformance with the North American Datum of 1983 ...

This 1m Digital Terrain Model (DTM) is derived from bare-ground Light Detection and Ranging (LiDAR) point cloud data from September 2005 for the Green Lakes Valley, near Boulder Colorado. This dataset is better suited for derived layers such as slope angle, aspect, and contours. The DTM was created from LiDAR point cloud tiles subsampled to 1-meter postings, acquired by the National Center for Airborne Laser Mapping (NCALM) project. This data was collected in collaboration between the University of Colorado, Institute of Arctic and Alpine Research (INSTAAR) and NCALM, which is funded by the National Science Foundation (NSF). The DTM has the functionality of a map layer for use in Geographic Information Systems (GIS) or remote sensing software. Total area imaged is 35 km^2. The LiDAR point cloud data was acquired with an Optech 1233 Airborne Laser Terrain Mapper (ALTM) and mounted in a twin engine Piper Chieftain (N931SA) with Inertial Measurement Unit (IMU) at a flying height of 600 m. Data from two GPS (Global Positioning System) ground stations were used for aircraft trajectory determination. The continuous DTM surface was created by mosaicing and then kriging 1 km2 LiDAR point cloud LAS-formated tiles using Golden Software's Surfer 8 Kriging algorithm. Horizontal accuracy and vertical accuracy is unknown. The layer is available in GEOTIF format approx. 265 MB of data. It has a UTM zone 13 projection, with a NAD83 horizonal datum and a NAVD88 vertical datum computed using NGS GEOID03 model, with FGDC-compliant metadata. A shaded relief model was also generated. A similar layer, the Digital Surface Model (DSM), is a first-stop elevation layer. A processing report and readme file are included with this data release. The DTM is available through an unrestricted public license. The LiDAR DEMs will be of interest to land managers, scientists, and others for study of topography, ecosystems, and environmental change. NOTE: This EML metadata file does not contain important geospatial data processing information. Before using any NWT LTER geospatial data read the arcgis metadata XML file in either ISO or FGDC compliant format, using ArcGIS software (ArcCatalog > description), or by viewing the .xml file provided with the geospatial dataset.

This 1:50,000-scale geologic map represents a compilation of the most recent geologic studies of the upper Arkansas River valley, between Leadville and Salida, Colorado. The valley is structurally controlled by an extensional fault system that forms part of the prominent northern Rio Grande rift, an intra-continental region of crustal extension. This work also incorporates new detailed geologic mapping of poorly understood areas within the map area and reinterprets previously studied areas, aided by lidar data that covers 59 percent of the map area. The mapped region extends into the Proterozoic metamorphic and intrusive rocks in the Sawatch Range west of the valley and the Mosquito Range to the east. Paleozoic rocks are preserved along the crest of the Mosquito Range, but most of them have been eroded from the Sawatch Range. Numerous new isotopic ages (U-Pb zircon ages for the intrusive Proterozoic and some Tertiary rocks adjacent to the valley and 40Ar/39Ar ages for the Late Cretaceous to Oligocene intrusive and extrusive rocks) better constrain the timing of both Proterozoic and Late Cretaceous to early Tertiary intrusive events. The U-Pb ages document widespread ~1,440-Ma granitic plutonism north of Buena Vista that produced batholiths that intruded an older suite of ~1,760-Ma metamorphic rocks and ~1,700-Ma plutonic rocks. As a result of extension during the Neogene and possibly latest Paleogene, the graben underlying the valley is filled with thick basin-fill deposits (Dry Union Formation and older sediments), which occupy two sub-basins, separated by a bedrock high near the small town of Granite. The Dry Union Formation has undergone deep erosion since the late Miocene or early Pliocene. During the Pleistocene, ongoing steam incision by the Arkansas River and its major tributaries has been interrupted by periodic aggradation. From Leadville south to Salida as many as 7 mapped alluvial depositional units, which range in age from early to late Pleistocene, record periodic aggradational events along these streams that are commonly associated with deposition of glacial outwash or bouldery glacial-flood deposits. Many previously unrecognized Neogene and Quaternary faults, some of the latter with possible Holocene displacement, have been identified on lidar imagery. This imagery has also permitted more accurate remapping of glacial, fluvial, and mass-movement deposits and has aided in the determination of their relative ages. Recently published 10Be cosmogenic surface-exposure ages, coupled with new geologic mapping, have revealed the timing and rates of late Pleistocene deglaciation. Glacial dams that impounded the Arkansas River at Clear Creek and possibly at Pine Creek failed at least 3 times during the middle and late Pleistocene, resulting in catastrophic floods and deposition of enormous boulders and bouldery alluvium downstream; at least two failures occurred during the late Pleistocene during the Pinedale glaciation.