I'd call and see if you can change the snowmobile trip. If you want to see Yellowstone try and get one of the tours in the vans with tracks or snow tires. That will actually allow you to look at the scenery instead of focusing on driving the snowmobile the whole time.

The off-road snowmobile trips are way more fun. We did the Togwotee pass trip a couple years back and it was a lot of fun.