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.

We developed the vegetation map for Petroglyph National Monument (PETR) using a strategy that combined automated digital image classification and direct analog image interpretation of aerial photography and satellite imagery. Initially, the aerial photography and satellite imagery were processed and entered into a GIS, along with ancillary spatial layers. We developed a working map legend of ecologically-based vegetation map units using the NVCS classification described in Chapter 2 as the foundation. The intent was to develop map units that targeted the plant-association level wherever possible, within the constraints of image quality, information content, and resolution. With the provisional legend and ground-control points provided by the field-plot data (the same data used to develop the vegetation classification), we conducted heads-up screen digitizing of polygons based on image interpretation, and supervised image classifications. The outcome was a vegetation map composed of a suite of map units defined by plant associations and represented by sets of mapped polygons with similar spectral and site characteristics. The PETR vegetation map is at a 1:12,000 scale with 0.25 ha minimum map unit size, and was designed to facilitate ecologically- based natural resources management.