These datasets consist of four, 1-meter spatial resolution digital surface models (DSMs) that were generated to orthorectify airborne multispectral imagery acquired in 2002, 2009, 2013, and 2021 for the Colorado River in Grand Canyon in Arizona, USA. These datasets also consist of a 1-meter spatial resolution digital elevation model (DEM) that was generated from the 2021 DSM. The DSMs and DEM were also produced to support development of additional GIS products. Elevation values are expressed as ellipsoid heights. These datasets also include accuracy assessments that were performed to show the limitations of estimating elevation from the DSMs and DEM pixels locations on the landscape. Data were acquired during periods of low steady Colorado River flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam.

The 2021 Digital Elevation Model (DEM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the ground surface at that point expressed as NAD83(2011) ellipsoid height. A Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from approximately 8,000 ft to 11,000 ft above mean sea level at 20-cm resolution with one Leica ADS100 digital push-broom multi-spectral sensor on each of two aircraft May 29, 2021 – June 4, 2021. The DEM was generated by removing the aboveground features from the DSM by filtering process. Data were collected during a period of low steady river flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam. The data are for the segment of the Colorado River corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The 2021 Digital Elevation Model (DEM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the ground surface at that point expressed as NAD83(2011) ellipsoid height. A Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from approximately 8,000 ft to 11,000 ft above mean sea level at 20-cm resolution with one Leica ADS100 digital push-broom multi-spectral sensor on each of two aircraft May 29, 2021 – June 4, 2021. The DEM was generated by removing the aboveground features from the DSM by filtering process. Data were collected during a period of low steady river flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam. The data are for the segment of the Colorado River corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The horizontal accuracy assessment dataset consists of spatial coordinate and elevation values of “hard points” identified in each digital surface model (DSM) dataset and their spatial location data from the geodetic control network maintained by the U.S. Geological Survey (USGS), Grand Canyon Monitoring and Research Center (GCMRC). Surveyed “hard points” represent stationary natural features, such as corners of large boulders, that are visible in aerial imagery and elevation datasets and are in the geodetic control network maintained by the USGS, GCMRC. The vertical accuracy assessment dataset consists of pixel elevation values extracted from the DSM and digital elevation model (DEM) datasets for 926 “control points”. Surveyed "control points" represent survey marks and benchmarks in the geodetic control network maintained by the USGS, GCMRC. Each “hard point” and control point is denoted by a unique identifier from the Grand Canyon survey control network database maintained by the USGS, GCMRC. All point location are denoted by the distance upstream or downstream along the river channel from Lees Ferry, AZ. The temporal extent of the data is for the years 2002, 2009, 2013, and 2021, and the spatial extent is for the segment of the Colorado River riparian corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The horizontal accuracy assessment dataset consists of spatial coordinate and elevation values of “hard points” identified in each digital surface model (DSM) dataset and their spatial location data from the geodetic control network maintained by the U.S. Geological Survey (USGS), Grand Canyon Monitoring and Research Center (GCMRC). Surveyed “hard points” represent stationary natural features, such as corners of large boulders, that are visible in aerial imagery and elevation datasets and are in the geodetic control network maintained by the USGS, GCMRC. The vertical accuracy assessment dataset consists of pixel elevation values extracted from the DSM and digital elevation model (DEM) datasets for 926 “control points”. Surveyed "control points" represent survey marks and benchmarks in the geodetic control network maintained by the USGS, GCMRC. Each “hard point” and control point is denoted by a unique identifier from the Grand Canyon survey control network database maintained by the USGS, GCMRC. All point location are denoted by the distance upstream or downstream along the river channel from Lees Ferry, AZ. The temporal extent of the data is for the years 2002, 2009, 2013, and 2021, and the spatial extent is for the segment of the Colorado River riparian corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The 2009 Digital Surface Model (DSM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify a four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the surface at that point expressed as NAD83 ellipsoid height. The DSM is a reflective surface DSM which provides elevation data on open ground (e.g. bare soil, rocks, and water), as well as aboveground terrain features including buildings, trees, and vegetation that cover otherwise open ground. The Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from approximately 5,950 ft to 9,000 ft above mean sea level at 20-cm resolution with a Leica ADS40 SH52 digital multi-spectral sensor May 25, 2009 – June 1, 2009. Data were collected during a period of low steady river flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam, however, tributary flows primarily from the Little Colorado River raised the approximate discharge to 9,000 cubic feet per second during the data collection from River Mile 61 (referenced by distance downstream from the confluence of the Paria River) down to River Mile 224 (Diamond Creek confluence) and possibly further downstream. The data are for the segment of the Colorado River corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The 2002 Digital Surface Model (DSM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify a four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the surface at that point expressed as NAD83 ellipsoid height. The DSM is a reflective surface DSM which provides elevation data on open ground (e.g. bare soil, rocks, and water), as well as aboveground terrain features including buildings, trees, and vegetation that cover otherwise open ground. The Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from a flight altitude of approximately 17,000 feet above river level (approximately 18,000 to 21,000 feet above mean sea level) at 22-cm resolution with a HRSC-AX push-broom sensor May 24 through June 5, 2002. Data were collected during a period of low steady flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam. The data are for the segment of the Colorado River riparian corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The 2009 Digital Surface Model (DSM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify a four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the surface at that point expressed as NAD83 ellipsoid height. The DSM is a reflective surface DSM which provides elevation data on open ground (e.g. bare soil, rocks, and water), as well as aboveground terrain features including buildings, trees, and vegetation that cover otherwise open ground. The Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from approximately 5,950 ft to 9,000 ft above mean sea level at 20-cm resolution with a Leica ADS40 SH52 digital multi-spectral sensor May 25, 2009 – June 1, 2009. Data were collected during a period of low steady river flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam, however, tributary flows primarily from the Little Colorado River raised the approximate discharge to 9,000 cubic feet per second during the data collection from River Mile 61 (referenced by distance downstream from the confluence of the Paria River) down to River Mile 224 (Diamond Creek confluence) and possibly further downstream. The data are for the segment of the Colorado River corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The 2013 Digital Surface Model (DSM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify a four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the surface at that point expressed as NAD83 ellipsoid height. The DSM is a reflective surface DSM which provides elevation data on open ground (e.g. bare soil, rocks, and water), as well as aboveground terrain features including buildings, trees, and vegetation that cover otherwise open ground. The Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from approximately 8,000 ft to 11,000 ft above mean sea level at 20-cm resolution with one Leica ADS80/82 digital multi-spectral sensor on each of two aircraft May 25, 2013 – May 30, 2013. Data were collected during a period of low steady river flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam. The data are for the segment of the Colorado River corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.

The 2013 Digital Surface Model (DSM) dataset consists of single band rasters at 1-meter pixel resolution that were generated to orthorectify a four band ortho imagery acquisition, and to support development of additional GIS products. Each pixel represents the elevation of the surface at that point expressed as NAD83 ellipsoid height. The DSM is a reflective surface DSM which provides elevation data on open ground (e.g. bare soil, rocks, and water), as well as aboveground terrain features including buildings, trees, and vegetation that cover otherwise open ground. The Digital Surface Model (DSM) was generated by automatic correlation of stereoscopic imagery collected from approximately 8,000 ft to 11,000 ft above mean sea level at 20-cm resolution with one Leica ADS80/82 digital multi-spectral sensor on each of two aircraft May 25, 2013 – May 30, 2013. Data were collected during a period of low steady river flow of approximately 8,000 cubic feet per second released from Glen Canyon Dam. The data are for the segment of the Colorado River corridor from Glen Canyon Dam downstream to Pearce Ferry, AZ.