These data were compiled for monitoring riparian vegetation change along the Colorado River. This file contains data recorded at 42 sandbars between Lees Ferry and Diamond Creek, AZ, which are sampled for both geomorphic and vegetation change annually. Field data contained here were collected from 2012 to 2016 in September and October of each year. Plant species cover values in 5441 1m^2 quadrat frames, locations and elevations of those sampling frames, slope and aspect, sample dates, temperature and precipitation data, and flood frequency parameters were either recorded in the field or calculated. Annual and seasonal climate variables were estimated from eight weather stations distributed along the river corridor from data aquired from Caster et al. 2014. Data collected between 1 February 2008 and 31 January 2011 were used, as the greatest number of weather stations were recording data with the fewest data gaps during this time. Data were linearly interpolated to sandbars lacking weather data based on distance from adjacent weather stations. Available climate variables included minimum and maximum annual temperature; mean annual, winter (November - April) and monsoon (May - October) precipitation; and mean annual humidity. Inundation and depth to water table were estimated for each plot using plot elevation (acquired from Kaplinski et al. 2014), the 15-minute hydrograph from Glen Canyon Dam (https://www.gcmrc.gov/discharge_qw_sediment/?), and the stage calculator developed for sandbars by Hazel et al. (2006). Discharge data from the 365 days preceding the vegetation surveys were used to calculate the proportion of that year, and the maximum number of contiguous days in which a plot was inundated; minimum, mean and maximum inundation depth; and elevation above river stage at 566m3s-1 (average daily peak flow).