I guess another way to help draw the narrow distinction between the two is to identify their food source. Those that have access to coastal food sources (namely salmon) are considered brown bears. From a scientific standpoint, they do take on a different name. This may be ugly but here goes based on memory. The grizzly is ursos arctos horribilis middendorffi. The brown bear gets a different designation in the place of middendorffi. I know someone out there can reign me in on the details of what I'm trying to get across.

Paul