AFAIK, there are no Grizzlies in the CONUS only Alaska. Their cousins the Browns are a different story.
Grizzlies ARE brown bears.
When we first got here we asked about bear protection. The consensus went like this:
1. 12 ga shotgun loaded with magnum bear slugs
2. .45-70 gov lever gun*
3. .30-'06 or .308 rifle*
4. .44 Rem Mag or larger revolver
(*Because they can also be used for moose hunting)
Any mention of bear spray or smaller calibers is met with scorn and derision or outright laughter.
There are grizzly bear populations in western Montana and NW Wyoming.