I lived in Choteau, wife grew up there. I packed and guided all over the Rockies to the west. The Bob and Scapegoat were loaded with grizzlies. Choteau is unique because it is so unsuspecting for Grizzlies, but they follow the river right to town. Most Bird hunters and out of towners would never think of griz in that area. It is flat and miles from the mountains. Just seems grizzlies are meaner around there too.
I truly believe it's because of food source. I spend a good amount of time fishing around grizzlies in AK and they are rarely aggressive and way more frequent of visitors. I believe they are so occupied with the fish and the competition for food is very low. I could be totally wrong, but this has been my observation of the two.