In 1948 Donald J. Lehmer published his synthesis "The Jornada Branch of the Mogollon Culture", the first such attempt regarding the prehistoric archaeology of south central New Mexico, far west Texas, and the northern part of the state of Chihuahua, Mexico. It was based on a few excavations and limited surveys in the El Paso, Las Cruces, and Alamogordo areas. Yet, he then generalized these few data to the mega-region stretching from the town of Carrizozo, NM on the north to Villa Ahumada, Chihuahua, Mexico on the south and from Deming, NM on the west to Carlsbad, NM on the east, largely on the basis of certain pottery types found throughout. In 1965, key members of the Lea County Archaeological Society situated in Hobbs, NM proposed an Eastern Extension of the Jornada Mogollon to include southeastern New Mexico east of the Pecos River, again on the basis of the same pottery types and the supposition that a few excavated remnants of structures throughout this additionally vast region represent southwestern style pithouses and pueblos.Since 1965, considerably more survey and excavation has been accomplished in Lehmer's and LCASs regions and all areas in between. Most of that work has been in connection with cultural resource management activities required by federal and state laws. It is now possible to update our perceptions and talking points about this quarter of New Mexico and adjacent areas in Texas. The present volume updates our information base (through its original completion in 2016) based on the author's nearly 50 years of direct experience with and rumination about southeastern New Mexico archaeology. It is acknowledged that this is only a beginning and that the coming decades will produce more information by which to bring ever increasing focus on the prehistory (and history) of this culturally and physiographically diverse part of the world. REGGE N. WISEMAN was born and raised in southeastern New Mexico. As an undergraduate he studied anthropology at the University of New Mexico under the mentorship of Florence Hawley Ellis, and as a graduate student at Arizona State University under Alfred E. Dittert, Jr. Wiseman was recruited for work at the Laboratory of Anthropology, Museum of New Mexico in 1971 where he worked on CRM projects until his retirement in 2000. He is especially interested in the Jornada Mogollon, the Jemez Mountains region, the Galisteo Basin, and the Reserve Mogollon of west-central New Mexico. At present he continues to conduct analyses of artifact collections and preparing detailed descriptive reports of CRM projects dating back to the 1950s that had not been completed because of lack of funding.