We did see 6 bears (4 in Yellowstone and 2 in the Beartooth Mountains). Here are our bear sightings (I didn't get a picture of the 4th bear in Yellowstone-we just saw the cub and it was pretty far away playing among fallen logs. We think the cub was a black bear.) The first bear we saw was a mama grizzly bear with 2 cubs who had found a bison carcass. She would eat off the carcass and then bury it with grass. She would leave and then come back later. Our second night in Yellowstone we went out after dinner looking for wildlife and didn't find any the way we went so we went south from our campground which took us to the Hayden Valley and that was where this mama grizzly bear was. We saw her at night but it was pretty dark. She was there again in the morning when we drove by the next time. She was there many other times as well-you could tell because there would be tons of cars parked alongside the road and a huge crowd of people on the hill overlooking the valley. There were always several rangers and by the end of our time there they had cones set up on the hill and people had to stay back behind them as not to agitate the mama bear. For Noah, this was a highlight of the trip. He wanted to tell everyone about it.
In the picture below you can see the mound on the right. That is where the bison carcass is and you can see how she buried it with dirt and grass.
We got VERY close to bison because we had 3 bison walk down the center line in the road and walk right past our car. Noah and Brian probably could have reached out and pet the bison if they had rolled down their window!
This was only part of the herd.