The Martian Chronicles has an interesting recap of a recent geology fieldtrip through Northern Arizona including the Chinle Formation of Petrified Forest National Park.
You can check out the Petrified Forest portion here and make sure to read about the rest of the trip as well and how it relates to new research on Mars.
BTW.... the unidentified paleontologist is Petrified Forest Fossil Preparator Matt Brown, the "other" paleontologist guide (holding up the outcrop) is Jeff Martz.
Shock Me like an Electric Eel
15 hours ago in Catalogue of Organisms