Loved Yellowstone, been there a couple of times. this spring my oldest daughter and I drove down to spring training. The Oregon coast was awesome. We spent a day at Joshua Tree National Park in California and I really loved that. Coming back from spring training we saw numerous national monuments and national parks among them, Montezuma Castle, El Morro National Monument (really cool!), Petroglyph National Mon. in New Mexico (a day out of the way, but worth it), Petrified Forest and Painted Desert, Grand Canyon, Arches, Zion and Bryce Canyon. It was a great trip. My daughter took about 4,000 pictures (not kidding!). There was one spot in southern Utah where we drove up a winding road on the side of a mountain with a cliff like you described, Tex. This was a narrow gravel road. I was really scared and would never do that again.