Provided is an excel spreadsheet which contains data used to estimate maximum potential shrub cover across a semi-arid grassland in Southern Arizona. Data was obtained using a classified shrub cover (mesquite) map of Las Cienegas National Conservation Area in Southeastern Arizona which was derived using 2017 NAIP imagery which is free available on EarthExplorer. Classified shrub cover map was created using an unsupervised ISO classification technique within ArcGIS. This shrub cover map was upscaled to 100m and a number of topoedaphic spatial layers were overlaid onto this shrub cover layer and their layers extracted per pixel. This data was then analyized within R using a segmented quantile regression approach to identify maximum shrub cover by topoedaphic characteristics at the 95th percent quantile. For sample of quantile code please contact the corresponding author. Topoedaphic variables analyzed in this data set are: Shrub Cover (%) Elevation (m) Slope Inclination (°) Slope Aspect (Cardinal Direction) Value 2 = North Value 3 = East Value 4 = South Value 5 = West Percent Clay between 0 to 5cm (%) Depth to bedrock (cm) Topographic Wetness index (TWI) (unitless with higher values representing more run-on/wetter conditions) Shrub cover was analyzed at the study site level and at the ecological site level.