Table 1. Factors hypothesized to limit grizzly bear density in interior ecosystems in North America and the variables we derived to index these factors.

Plant productivity	Vegetation type1	Diet	Competition with black bears	Human disturbance	Human-caused mortality
annual precipitation	tree10	salmon presence	tree10	tree10	human density
annual temperature	tree25	%salmon in diet	tree25	tree25	human+livestock density
annualized NDVI	herb50	%terrestrial meat in diet	black bear presence	livestock density	human+livestock density within 10 km2
evapotranspiration	herb75			human density	human+livestock density within 50 km2
ruggedness	herb100			human+livestock density	mean recorded human-caused mortality in past 10 years
				human+livestock density within 10 km2
				human+livestock density within 50 km2

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.