I never thought that I would see a grizzly here. But after the first two hours in the park I saw two grizzlies. Two days later there was a grizzly with her two cubs and luckily they were very relaxed. I know we were way too close but it was cute. And the car gives you some saftey.
Best places to watch is the northern part of the loop. Most of the grizzlies were very close to the road (i.e. the grizzly with the cubs just 5m beside the road).
The Hayden Valley is very good for bisons. With luck there are big herds near the road.
In Mammoth, there was a big herd of elks living between the houses.
An other good place is the Lamarvalley in the northeast of the park. Big bisons herds and with luck wolfs.
Around Tower Falls there is a lot of bear activity. So go there if you want to see some bears.
Now the pictures, enjoy.