The first attached photo was shot at the extreme end of my camera ability to zoom. I had no desire to get closer. I took the photo as I was leaving Waterton park which is north of Glacier by a day ride. I think it was a black bear, not a grizzly, both species live in the area.
The second photo is my Sherpa on that trip. The little bump hanging down from the top tube just aft of the head tube was my bear bell, but the roads were not bumpy enough to keep ringing my bear bell, so there was the danger that I could ride up to a bear without it hearing me approach.
I recall reading a few years ago that a hiker in Glacier had been killed by a grizzly. They found a camera nearby. There were a series of photos on that camera of a grizzly, the bear was closer on each photo and the last photo suggested that the grizzly was really close to the camera at that time. So, don't try to get the really good photos of the grizzly, that might be your last series of photos.