Nov 21, and we are still in the Valley of Fire...We did some hiking on some of the many trails in the park and came across some petrified logs...These trees were buried in a mudflow in the age of dinosaurs and became fossilized. 

(Click on any of these pictures to see a larger view)

In fact the rock formations in the park are fossilized sand dunes from the same era.  They are a deep red caused by iron oxide (rust) in the sand.

It is obvious that these were once sand dunes by the cross bedding that is seen in these rocks everywhere in the Valley.  This is a classic example of cross-bedding...see the layers at different angles?