Jim, I was there a couple years ago during the last week of June. I found the best wildlife activity in the area from Mammoth Hot Springs up through the Lamar Valley. Wolves (at a distance); herds of bison; herds of Elk; sometimes almost surrounding the Mammoth Hotel grounds; and both Grizzly and Black Bear in Lamar Valley and the Roosevelt-Tower area. Lots of bison always hang around the Old Faithful area, too, like this big boy:



Nice scenery up towards Tower Falls (Look for the eagle nest on a rocky pinnacle below the road at an overlook.)

The drive up to Mt. Washburn is quite scenic and you might still find some snow up there. Here's a pano on the way to Mt. Washburn, shown at the far right. Pardon the poor quality, it was taken with a 2mp Olympus.



I also saw a lot of elk and some bear in the Southern Area toward Jackson Hole but didn't travel the road towards West Yellowstone.

Hope you have a great trip.

Dick:)