This is reported and pictures submitted by a long time Alpine Shop customer, Tom Piotter.
Here is the picture of the Black Wolf that crossed the road and came by our car as we were turning around about 15-20 feet away. We were on our way to the Old Faithful Lodge from the Mammoth Springs Lodge. Most of the Wolf population in Yellowstone is in the Slough Creek area were they were released. This one came out of the small fir trees right were I was standing only minutes before.
Click to enlarge.