We could see the monuments from the main road while we were stopped for road construction. Another driver was making good use of their sunroof. There was a long line to get into the park, too.
We tried the self-drive road through the valley — rental cars go everywhere, right? But it was a bit much for our rental; we got stuck once and bottomed out twice so we turned around and drove back to the visitor center. They do offer small bus tours.
We ate our lunch on the terrace at the visitor center, which had nice views also. And long lines at the restrooms due to tour busses. We got to see a dog all rigged up to ride on a motorcycle.