Maps. New Mexico. Geology of Nacimiento Mountains, San Pedro Mountain, and adjacent plateaus in parts of Sandoval and Rio Arriba Counties, N. Mex., geologic map by G. H. Wood and S. A. Northrop, stratigraphy and paleontology by S. A. Northrop and G. H. Wood, compilation by M. J. Cowan; oil and gas investigations, preliminary map 57 [with text]. Scale 1 m.=0.7 in. n. p.