National Park Quiz

I will build this a little at a time.

Which three national parks have cave names ?
Which state has the most national parks ?
Which three national parks have valley names ?
Which states' national parks are adjacent in the alphabetical listing ?
Which four national parks have plant names ?
Which two national parks are not in any state ?
Which two national park names contain their state names ?
Which five national parks have canyon names ?
What are the five "grand" and "great" national parks ?
What are the Black and White National Parks ?
We have Great Sand Dunes.
What's the other Sand park, and
What's the other Dunes park ?
Sequoia and Kings Canyon share a boundary.
Which three pairs of parks nearly touch (within ten miles) ?

To be continued . . .