Named as middle formation (of 3) of Madera Group (raised in stratigraphic rank), Manzano Mountains, San Juan and Estancia basins, NM. Named for Wild Cow Spring in NE1/4 sec 19, T4N, R5E, Torrance Co. Type section for formation and for its three new members, Sol se Mete, Pine Shadow, and La Casa, designated on west side, Priest Canyon, sec 7, T3N, R5E, Valencia Co. Reference sections designated at Los Moyos, Torrance Co, and at Sol se Mete, Bernalillo Co. Consists of rhythmic sequences of arkosic sandstone and conglomerate, gray to yellow siltstone and shale, and thin- to thick-bedded gray limestone. Is about 690 +/-ft thick at type; nearly 800 ft thick at Los Moyos; almost 650 ft thick at Sol se Mete. Overlies Los Moyos Limestone; underlies Bursum Formation, both of Madera Group at most localities; may underlie Abo Formation where Bursum cannot be distinguished. Is of Late Pennsylvanian, Missourian and Virgilian age. Contains fusulinids. Probably equivalent to Atrasado Member of Madera Limestone of Valencia and Socorro Cos.

Source: GNU records (USGS DDS-6; Denver GNULEX).