In 1997, a group of scholars assembled at the Amerind Foundation in Dragoon, Arizona, for five and one-half days of secluded focused discussion on the archaeology and history of an area largely absent from archaeological reports and history books, southeastern Arizona and southwestern New Mexico. The researchers present at the seminar included Bruce Masse, Anne Woosley, Allan MacIntyre, Jeff Altschul, John Douglas, Jeff Clark, Bill Doolittle, Jim Neely, Jerry Howard, Peggy Nelson, Jonathan Mabry, Tom Sheridan, and the author. The discussion session was followed by a field visit to some nearby sites, and in June of 1998, the group was led on an extensive tour of the Safford Basin and the lower San Pedro Valley so that everyone could see, firsthand, the setting and settlement in these prehistorically heavily populated regions. Although all the researchers agreed there was utility in treating the assigned study area as a useful geographical region, they were initially hampered by the lack of a term with which to refer to it. Cultural labels did not fit, because as a region, it trended, at times, one way or another — Hohokam, San Simon, Dragoon, Mimbres, Mogollon, Salado, or Casas Grandes — depending on time and personal bent. Consequently, the researchers were asked to look at such labels with a critical eye in their studies. Terms such as "international four corners" and the much longer "southeastern Arizona and southwestern New Mexico" could be defined and used, although they are unwieldy. In fact, the latter term is used here to some degree for lack of another unambiguous geographical referent. Allan McIntyre suggested the term "a land between," which captures the essence of the region and theme of this volume, for it truly is a land caught between the better known and less known, between Mimbres and Hohokam, between Salado and Casas Grandes. The researchers who contributed to this volume who had conducted fieldwork in the region were asked to use it as an opportunity to publish much more than the usual amount of data for a synthetic volume of this sort. Because the region has few population centers and minimal local level cultural resource management regulations, the explosion of contract archaeology work that has transformed the discipline's knowledge of the Tucson-Phoenix corridor barely touched the Land Between—and most of that work occurred after the 1997 seminar. Consequently, much of the fieldwork in the region was conducted on shoestring budgets and private funding. Even part of one of the largest contract projects in the region, the work along a proposed highway route in the lower San Pedro Valley, which resulted in the excavations at the Peppersauce Wash sites — Alder Wash Ruin, AZ BB:6:9 (ASM), Una Cholla, AZ BB:6:18 (ASM), and Dos Bisnagas, AZ BB:6:7 (ASM)—was never published due to funding cuts from the highway department. With the Amerind Foundation setting a strong precedent from the work of Charles Di Peso, who published his raw data in exhaustive and very useful detail, it seemed only fitting that this volume should strive to do as much as possible to get information out to interested readers. As a result of the data focus of the volume, the reader will encounter some extreme swings in the lengths and detail included in the regional summaries, a direct result of the quantities of new or previously unpublished data available to the researchers involved. For example, the extensive unpublished data accessible to Masse, Gregonis, and Slaughter from their work in the lower San Pedro resulted in a much more data rich and lengthy chapter than the chapters by Douglas on the San Bernardino Valley, and Altschul, Vanderpot, Quijada, and Heckman on the upper San Pedro. For the San Bernardino Valley, there has not been as much work, so there are no data to publish. Much of the work from the middle and upper San Pedro has been published in technical reports in recent years, so it made more sense for the authors to summarize this work for a broader audience.