The Petrified Forest Member is a stratigraphic unit of the Chinle Formation in Arizona, Colorado, New Mexico, Nevada, and Utah.

Beds (are in alphabetical order, asterisks (*) indicate usage by the U.S. Geological Survey, other usages by state geological surveys):[2] In the Chama Basin of New Mexico, the Chinle Formation is promoted to group status and the Petrified Forest Formation has the following members:[3] The Mesa Montosa Member is up to 22 meters (72 feet) thick and is mostly composed of sandstone (44%) and mudstone (35%), with a lesser proportion of siltstone (20%).

The Painted Desert Member is up to 176 meters (577 feet) thick and is primarily reddish brown bentonitic mudstone.

Correlative beds of similar lithology are found throughout west-central and central New Mexico and the Four Corners.

Fossils include archosaurs, procolophonids, metoposaurid amphibians, semionotid fish, a decapod, a conchostracan, and unionid bivalves.