Factors hypothesized to limit grizzly bear density in interior ecosystems in North America and the variables we derived to index these factors.

Appendix S1 for detailed description of GIS derived variables. We digitized the study area boundary for each study area and calculated the average for each index using a GIS. See Table S1 in
 =  the proportion of the study with pixels rated as >50% herb/shrub.1 This is the sum of all pixels with >the stated percentage of described cover. For example, herb50
2 This is the mean human and livestock (sheep and cattle) density (summed) for the area within 10 or 50 km of the study area boundary.