You be the referree. These photos were all recently submitted with sighting reports.
So, what features make a big brown bear a grizzly? Black bears and grizzlies overlap in both size and color.
Grizzlies have a large, defined shoulder hump. A big block head with small looking ears. Large claws, very large indeed. A face profile that is dished.
Black bears have a small or no defined hump. Large ears compared to their head size. A long snout that has a face profile that is straight. Claws that are rather small.
Most folks do not want to go up to the bear and examine it's claws. However a good track will tell you if the bear was a black bear or a grizzly.
Learn more at the GBOP website about identifying bears.
If you see a grizz, call 1.800.WOLFBEAR or report the sighting at the GBOP website.
Alas, none of these photos can be classified as a grizzly. Therefore, they are most likely large brown black bears.