This is from day two of our trip to Yellowstone NP.

We were being driven to the Old Faithful Snow Lodge via these 1960's vintage
Snow Coaches. It was quite cosy as we packed nine people into these coaches.
They had hatches on the roof, so we could take pictures of the wildlife and
scenery.

A couple of times we encountered Bison marching down the road, which stopped all of
the traffic as we waited for them to pass.