Thank you @lidja! I highly recommend a visit - but try to stay away from the summer months. The park is overcrowded during that time. The park service has announced they are going to try a reservation system for driving in certain areas of the park but that won't start until 2020.
I wish they would close the roads entirely and require that everyone walk, bike, or ride the buses. I guess we'll need to wait to see if the reservation system works. In the meantime, it's quite empty in early spring and is reasonable once school starts again.