The Colorado Plateau Coring Project-1 recovered ~ 850 m of core in three holes at two sites in the Triassic fluvial strata of Petrified Forest National Park, AZ, USA. The cores have abundant zircon, U-Pb dateable layers (210–241 Ma) that along with magnetic polarity stratigraphy, validate the eastern US-based Newark-Hartford astrochronology and timescale, while also providing temporal and environmental context for the vast geological archives of the Triassic of western North America.