The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles.

Aerial photointerpretation was conducted by the Project Manager with the help of an assistant mapper between the fall of 2012 and fall of 2014, using the 2009 1-meter spatial resolution National Agriculture Imagery Program (NAIP) imagery for the Utah portions of GLCA, and the 2010 1-meter spatial resolution NAIP for the Arizona portions of GLCA as the base image layers. The project used the program standard minimum mapping unit (MMU) of 0.5 ha with few exceptions. The majority of the mapping work was performed using ArcGIS editing tools and onscreen, heads-up digitizing, aided by ancillary datasets. Map classes were defined for the project by the primary photointerpreter (PI) with input from the GLCA Chief Scientist. A draft vegetation map and associated spatial database were completed for the Orange Cliffs section of GLCA in the summer of 2014 and for the remainder of GLCA/RABR in the late fall of 2014.

Forty-eight map classes represented by 33,691 polygons were developed for GLCA/RABR. A total of 31,058 polygons represent 37 natural or semi-natural vegetation map classes covering 75% of the mapping project area. Eleven additional land use/land cover and geologic map classes describe 2,633 polygons (25% of the area). Average polygon size across all map classes is 23.1 ha (57.2 acres). Blackbrush Shrublands had the highest number of polygons (5,560) polygons covering 14.5% of the total vegetated mapping area.