The lower conglomerates contain volcanic debris, while the upper beds contain sparse nonvolcanic rock fragments.

The group is present around Elephant Butte Reservoir, in the Caballo Mountains, and under much of the Jornada del Muerto.

The Jose Creek Formation is interpreted as mudflow or alluvial fan deposits emplaced in a humid tropical to semitropical environment.

ratonensis, Salix, Cinnamomum, Sabalites montana, Araucarites longifolia, Ficus planicostata, and Sequoia.

[19] Spencer G. Lucas and his coinvestigators disagreed on the basis of fossil evidence, placing the former formation in the Eocene.

The Double Canyon Formation is over 425 meters (1,394 ft) of mudstone with some sandstone and conglomerate found between Elaphant Butte Reservoir and the Fra Cristobal Mountains to the northeast.