It is proposed that the abandoned name “Wolfcamp Formation” be reinstated as a formal lithostratigraphic unit for a lower Permian (Cisuralian) to Upper Pennsylvanian interval comprising interbedded dark gray to black basinal mudstone and limestone in the subsurface Delaware Basin in Texas and New Mexico according to the guidelines of the North American Stratigraphic Code. The proposed Wolfcamp Formation is defined as the interval from the base of the lowermost sandstone of the Bone Spring Formation to the top of the Strawn Formation/Group at the proposed reference section of the Ross Draw 7 well drilled in southern Eddy County, New Mexico. Adoption of the proposed Wolfcamp Formation as a formal lithostratigraphic unit in the Delaware Basin is subject to acceptance and usage by others following publication of this proposal. It is anticipated that formal adoption of the Wolfcamp Formation will encourage others to formally define the correlative lithostratigraphic unit in the Midland Basin, Texas.