GIS maps of aspect, elevation, slope, soil type and vegetation type of the Pawnee National Grasslands (PNG). The two polygons represent the east and west sections of the PNG. Beers et al. (1966) transformation was used for aspect, ranging from 0 (SW) to 2 (NE); elevation ranges from 1309–1800 in 100 m intervals; slope ranges from low (0–10%) to medium (10–30%) to steep (>30%); vegetation and soild are based on previous classifications (see text).