The Grand Teton National Park is not part of Yellowstone, rather it is its own park. The road between the two is called the "John D. Rockefeller, Jr. Memorial Parkway." Mr. Rockefeller didn't want all of us paying twice to get into these two parks, so be bought the land between the two and gave it over to us. I learned a bit more about our national park system and the visionaries who created it (Rockefeller being one of them).
Of course the next day was clear and sunny. What is amazing is that the road is at an elevation of about 7000 ft above sea level... and those darn peaks just keep going up. I'm on a flat road that is higher than the top of Mt Washington!