Tectonic map of Rio Grande region from New Mexico-Colorado Border to Presidio, Texas
— L. A. Woodward, J. F. Callender, J. Gries, W. R. Seager, C. E. Chapin, R. E. Zilinski, and W. L. Shaffer

The idea of compiling a tectonic map of the Rio Grande region was stimulated by the Geological Society of America Penrose Conference on the Rio Grande rift in August 1974. During the course of the conference it became clear that many geologic problems related to the rift were being studied: the origin and extent of the rift, geomorphic and tectonic evolution, relationships of volcanism, mineral deposits, geothermal energy and seismicity, the quality and supply of groundwater, and many more. It seemed to us that an up-to-date tectonic map of at least part of this region would be useful to these investigators. The location of the Las Cruces Country at the debatable southern end(?) of the rift and the number of guidebook papers dealing with various aspects of the rift made the 1975 guidebook an appropriate place to publish the tectonic map (in pocket).