To examine potential influence of tributaries on riparian habitat complexity along ~216 km of the Colorado River in Utah and ~300km of the Dolores River in Colorado and Utah, we first classified fluvial features and land cover of the bottomland on remotely sensed imagery. We then examined riparian and geomorphic patterns within the near channel zone with variably-sized spatial units. We used supervised image classification to create a 2-m resolution map of the primary land cover types within bottomlands of the Colorado and Dolores rivers, including two anthropogenic classes, four vegetation classes, bare ground, water and shadow. We selected these cover classes as major vegetation and land cover types that could be discerned from imagery. Our minimum mapping unit was 16m2. We were unable to map channel areas with flowing or standing water using supervised image classification, so we hand digitized channels based on a visual inspection of 2-m resolution imagery. We classified 6 channel classes based on their geomorphic characteristics and location within the river network (i.e., tributary vs. primary channel) or relation to the primary channel (e.g., split flow channels and secondary channels) and converted these to a 2-m resolution image (adapted from Moore et al 2012). We then combined land cover and channel classes to produce a single map representing both cover types along the Colorado and Dolores rivers. Our classification was based on 2-m resolution, multi-spectral (RGB NIR) aerial photographs for September 2013 and 2014 from the USDA National Agriculture Imagery Program (NAIP; http//www.fsa.usda.gov). We identified tributary junctions using the National Hydrography Dataset Plus Version 2 (NHDPlus V2) using the medium resolution (1:100,000 scale) National Hydrography Dataset (NHD) (http://nhd.usgs.gov/). To more accurately locate tributary junctions, we extracted flowlines corresponding to tributaries and converted each flowline to a point located at the terminus proximal to the channel centerline. We manually corrected tributary junction point locations with the NAIP images. We defined the near channel zone as within 20 meters of the edge of the Dolores low flow channel and within 100 meters of the edge of the Colorado low flow channel. These distances represented the average widths of the low flow channel for the two rivers. We assumed that habitat conditions closer to the channel would be more strongly influenced by fluvial processes and less strongly influenced by land management (e.g., farming, road development). We created spatial units for analysis within the near channel zone with Thiessen polygons - a polygon containing a point and defining an area closest to the point relative to all other systematically placed points (Fortin and Dale 2005). Beginning at the upstream study site boundary for each river, we placed regularly spaced points at three intervals: 10-, 25-, and 100-m to capture patterns for different sized spatial units around tributary junctions. For each point, we created a Thiessen polygon. Our use of Thiessen polygons as spatial units followed the example of other researchers (Alber and Piegay 2011). This data release includes shapefiles and associated metadata for: land and channel cover types along both rivers; tributary junction locations along both rivers; and the 10-, 25-, and 100-m Thiessen polygons along both rivers. Alber A., and Piégay H., 2011, Spatial disaggregation and aggregation procedures for characterizing fluvial features at the network-scale: application to the Rhône basin (France): Geomorphology, v. 125, p. 343-360. Fortin M.J., and Dale M.T., 2005, Spatial analysis: a guide for ecologists: Cambridge, Cambridge University Press, 365 p. Moore K., Jones K., Dambacher J., and Stein C., 2012, Aquatic inventories project methods for stream habitat surveys: Corvallis, OR, Conservation and recovery program, Oregon Department of Fish and Wildlife, 74 p.

The 'Channel Width' shapefile data are measurements of the active channel width of the Green River at 1-km intervals in and near Canyonlands National Park, Utah. The active channel was defined as the area of the wetted, or inundated, channel as visible on aerial photographs plus the area of bare (free of vegetation) sand and gravel bars. The active channel for each aerial photograph series was hand digitized on a computer screen in ArcGIS version 9.2. The 'Mineral Bottom' csv data are river channel cross-sections for a 3-km study reach of the Green River upstream from Mineral Bottom, Utah. The study reach is near the mouth of Hell Roaring Canyon, 5 km upstream from the Mineral Bottom boat ramp, which is 85 km upstream from the confluence of the Green River with the Colorado River. Six cross-sections were originally established by the U.S. Fish and Wildlife Service in June 1995. Additional cross-sections were added by Utah State University in August 1995. A subset of the cross-sections (where original monuments were found) were re-surveyed by the U.S. Geological Survey Grand Canyon Monitoring and Research Center in cooperation with Utah State University in June 2015. These raster data are aerial images and digital elevation models (DEMs) for segments of the Green River in and near Canyonlands National Park, Utah. The aerial images depict the river channel and adjacent floodplains for most of the corridor of the Green River in Canyonlands National Park. The images were aquired from public sources and orthorectified and mosaiced for this study. The DEMs cover the river channel and adjacent floodplain for the Fort Bottom segment of the Green River within Canyonlands National Park and included both bathymetric and topographic data. The bathymetric data were collected by the U.S. Geological Survey Grand Canyon Monitoring and Research Center with funding provided by the National Park Service. The topographic data are airborne lidar data that were collected for the state of Utah by a contractor.

The 'Channel Width' shapefile data are measurements of the active channel width of the Green River at 1-km intervals in and near Canyonlands National Park, Utah. The active channel was defined as the area of the wetted, or inundated, channel as visible on aerial photographs plus the area of bare (free of vegetation) sand and gravel bars. The active channel for each aerial photograph series was hand digitized on a computer screen in ArcGIS version 9.2. The 'Mineral Bottom' csv data are river channel cross-sections for a 3-km study reach of the Green River upstream from Mineral Bottom, Utah. The study reach is near the mouth of Hell Roaring Canyon, 5 km upstream from the Mineral Bottom boat ramp, which is 85 km upstream from the confluence of the Green River with the Colorado River. Six cross-sections were originally established by the U.S. Fish and Wildlife Service in June 1995. Additional cross-sections were added by Utah State University in August 1995. A subset of the cross-sections (where original monuments were found) were re-surveyed by the U.S. Geological Survey Grand Canyon Monitoring and Research Center in cooperation with Utah State University in June 2015. These raster data are aerial images and digital elevation models (DEMs) for segments of the Green River in and near Canyonlands National Park, Utah. The aerial images depict the river channel and adjacent floodplains for most of the corridor of the Green River in Canyonlands National Park. The images were aquired from public sources and orthorectified and mosaiced for this study. The DEMs cover the river channel and adjacent floodplain for the Fort Bottom segment of the Green River within Canyonlands National Park and included both bathymetric and topographic data. The bathymetric data were collected by the U.S. Geological Survey Grand Canyon Monitoring and Research Center with funding provided by the National Park Service. The topographic data are airborne lidar data that were collected for the state of Utah by a contractor.

With the help of local and regional natural resource professionals, we developed a broad-scale, spatially-explicit assessment of 146 miles (~20,000 acres) of the Colorado River mainstem in Grand and San Juan Counties, Utah that can be used to support conservation planning and riparian restoration prioritization. For the assessment we: 1) acquired, modified or created spatial datasets of Colorado River bottomland conditions; 2) synthesized those datasets into habitat suitability models and estimates of natural recovery potential, fire risk and relative cost; 3) investigated and described dominant ecosystem trends and human uses, and; 4) suggested site selection and prioritization approaches. Here, we make available to the public spatial data associated with this work. The data include 51 shape files: 6 of these are related to fluvial geomorphology and hydrology; 1 contains riparian vegetation and surrounding land cover types; 30 are related to habitat or conservation element models (including model components and model results); and 14 are related to supplemental models including the relative cost of restoration, site recovery potential, and fire models. The data released here are associated with a publication that describes the project and results in more detail: Rasmussen, C.G., and P.B. Shafroth. 2016. Conservation planning for the Colorado River in Utah. Colorado Mesa University, Ruth Powell Hutchins Water Center, Scientific and Technical Report No. 3. 93p.

These data consist of rectified aerial photographs, measurements of active channel width, measurements of river and floodplain bathymetry and topography, and ancillary data. These data are specific to the corridor of the Green River in Canyonlands National Park between Horseshoe Canyon and Deadhorse Canyon, Utah. The time period for these data are 1940 to 2018. The 'Channel Width' shapefile data are measurements of the active channel width of the Green River at 1-km intervals in and near Canyonlands National Park, Utah. The 'Mineral Bottom' csv data are river channel cross-sections for a 3-km study reach of the Green River upstream from Mineral Bottom, Utah. The study reach is near the mouth of Hell Roaring Canyon, 5 km upstream from the Mineral Bottom boat ramp, which is 85 km upstream from the confluence of the Green River with the Colorado River. Six cross-sections were originally established by the U.S. Fish and Wildlife Service in June 1995. Additional cross-sections were added by Utah State University in August 1995. A subset of the cross-sections (where original monuments were found) were re-surveyed by the U.S. Geological Survey Grand Canyon Monitoring and Research Center in cooperation with Utah State University in June 2015. The raster data are aerial images and digital elevation models (DEMs) for segments of the Green River in and near Canyonlands National Park, Utah. The aerial images depict the river channel and adjacent floodplains for most of the corridor of the Green River in Canyonlands National Park. The images were acquired from public sources and orthorectified and mosaiced for this study. The DEMs cover the river channel and adjacent floodplain for the Fort Bottom segment of the Green River within Canyonlands National Park and include both bathymetric and topographic data. The bathymetric data were collected by the U.S. Geological Survey Grand Canyon Monitoring and Research Center with funding provided by the National Park Service. The topographic data are airborne lidar data that were collected for the state of Utah by a contractor. The lidar data are available at https://doi.org/10.5069/G9RV0KSQ.

These data consist of rectified aerial photographs, measurements of active channel width, measurements of river and floodplain bathymetry and topography, and ancillary data. These data are specific to the corridor of the Green River in Canyonlands National Park between Horseshoe Canyon and Deadhorse Canyon, Utah. The time period for these data are 1940 to 2018. The 'Channel Width' shapefile data are measurements of the active channel width of the Green River at 1-km intervals in and near Canyonlands National Park, Utah. The 'Mineral Bottom' csv data are river channel cross-sections for a 3-km study reach of the Green River upstream from Mineral Bottom, Utah. The study reach is near the mouth of Hell Roaring Canyon, 5 km upstream from the Mineral Bottom boat ramp, which is 85 km upstream from the confluence of the Green River with the Colorado River. Six cross-sections were originally established by the U.S. Fish and Wildlife Service in June 1995. Additional cross-sections were added by Utah State University in August 1995. A subset of the cross-sections (where original monuments were found) were re-surveyed by the U.S. Geological Survey Grand Canyon Monitoring and Research Center in cooperation with Utah State University in June 2015. The raster data are aerial images and digital elevation models (DEMs) for segments of the Green River in and near Canyonlands National Park, Utah. The aerial images depict the river channel and adjacent floodplains for most of the corridor of the Green River in Canyonlands National Park. The images were acquired from public sources and orthorectified and mosaiced for this study. The DEMs cover the river channel and adjacent floodplain for the Fort Bottom segment of the Green River within Canyonlands National Park and include both bathymetric and topographic data. The bathymetric data were collected by the U.S. Geological Survey Grand Canyon Monitoring and Research Center with funding provided by the National Park Service. The topographic data are airborne lidar data that were collected for the state of Utah by a contractor. The lidar data are available at https://doi.org/10.5069/G9RV0KSQ.

These data were compiled to assess the status and trends of riparian plant communities along the Colorado River between Glen Canyon Dam and Lake Mead, AZ. Three metrics have been proposed to evaluate the "Riparian Vegetation" goal identified in the Glen Canyon Dam Adaptive Management Program's Long Term Experimental and Management Plan (U.S. Department of Interior, 2016). The three metrics are total living plant cover, the proportion of living cover composed of native species, and native species richness. Current policies for Glen Canyon Dam operations result in three longitudinal bands within the riparian area that are flooded at different frequencies. The band, or hydrologic zone, that is most frequently inundated is referred to here as the “active channel” or “AC.” This includes all areas inundated by releases up to 25,000 cubic feet per second (707 m3/s). The “active floodplain” or “AF” is inundated by high flow experiments and includes areas that are inundated by releases between 25,000 cubic feet per second and 45,000 cubic feet per second (1,274 m3/s). The “inactive floodplain” or “IF” is the area along the river that is inundated by releases over 45,000 cubic feet per second, which is not planned under current policies. The metrics are assessed for each of these hydrologic zones. Data from the Grand Canyon Monitoring and Research Center's riparian vegetation monitoring protocol (Palmquist and others, 2018) can be used to evaluate these metrics, which is what is provided here. In short, 80-100 sample sites are randomly selected each year. These sites include debris fans, eddy sandbars, and channel margins. At each randomly selected sample site, ocular cover estimates of each plant species occurring in 1-m2 quadrats spanning the hydrological zones are recorded, along with an estimate of total living plant cover and associated environmental variables. The first metric, total living plant cover, consists of two pieces of data; plant occurrence (a plant is present in the sample frame) and plant cover (proportion of the sample frame covered with living plants). Cover is represented by both an ordinal cover class (1, 2, 3, 4, 5, 6, etc.) and the midpoint of the cover class value (0.01%, 0.5%, 1%, 5%, 10%, 15%, etc). The proportion of native cover is the sum total of native plant cover divided by the sum total of plant cover (native plus nonnative cover) for a sample frame. Native plant richness is the total number of native species rooted inside a sample frame. The total living plant cover data are available for 2016 through 2023. The native cover and richness data are available for 2014 and 2016 through 2023.

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).

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 workbook contains spatial data on the hydrology, sedimentology, and vegetation extent within the Colorado River corridor from 60 to 78 miles (97 to 125 kilometers) downstream from Glen Canyon Dam, Arizona. In combination with the accompanying MATLAB scripts, these data were used to generate the results within the accompanying manuscript (Kasprak et al., Quantifying and Forecasting Changes in the Areal Extent of River Valley Sediment in Response to Altered Hydrology and Land Cover). Specifically, the datasets include (a) the daily mean or estimated/measured maximum discharge for the Colorado River at Lees Ferry (USGS #09380000) from 1921 to 2016, (b) the estimated daily maximum discharge for the future period 2016-2036, (c) the pre-dam hydrograph record from 1921-1963, (d) the post-dam hydrograph record from 1963-2016, and the pre- and post-dam extent of bare sand within the study reach, accounting for the influence of vegetation encroachment during that time.