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.

The RIGR vegetation map consists of 7,284 polygons totaling 34,506 acres (13,971 hectares) with an average polygon size of about 5 acres (2 hectares). The small polygons are due in part to the detailed mapping, the importance of delineating rare and non-native vegetation types, and the arbitrary splitting of continuous polygons into smaller areas due to RIGR’s unique boundary that follows the active mid-channel of the river. The mapping is also finely detailed since the 2015 TOP imagery was of high resolution allowing for very small stands of vegetation to be accurately mapped. Figure 21 shows an example of the detailed RIGR vegetation mapping centered on the Stillwell and La Linda area.Based on the final vegetation layer, about 3% (1,164 acres) consisted of open water, less than 1% (270 acres) was developed and 96% (33,074 acres) were vegetated. Of the vegetated total, less than 1% (146 acres) was forested or wooded, 65% (22,306 acres) were shrublands, 6% (2,154 acres) were dominated by herbaceous species, and 25% (8,468 acres) contained sparse vegetation. The largest single map unit was the Calcareous Mixed Desert Shrub (S_CDS) type covering 15% (5,245 acres) of the project area. General mapping trends include 71% (24,383 acres) of the project area was mapped as a dry upland scrub or shrubland type, 5% (1,802 acres) was mapped as an upland wash, drainage, or mesic shrub type, and 20% (6,889 acres) was mapped as a riparian type. Non-native vegetation map units were split between 4% (1,411 acres) for herbaceous vegetation and 2% (726 acres) for shrubs.