It's a two-for-one National Park deal! One entry fee got me into both the Painted Desert National Park and the Petrified Forest National Park. After paying my admission, the ranger asked me if I had any petrified wood in my car. I said yes, that I had bought some at the Rainbow Rock Shop in Holbrook. She asked if I had a receipt and yes, I did. I noticed a sign later when I left the park that vehicles can be subject to search, as they don’t want anyone poaching petrified wood from the forest.