Archaeological test excavations and the monitoring of environmental testing was conducted by Desert Archaeology, Inc., at the location of the proposed Phoenix Federal Building and United States Courthouse in Phoenix, Arizona. The project area consists of historic blocks 72 and 73 of the Original Phoenix Townsite. Archival research had indicated that the area was originally settled between 1875 and 1885 and that the property had been the site of dozens of residential and commercial structures. The archival study recommended that an archaeological testing program be initiated to determine whether significant cultural resources were present (Hummert 1994). Testing was conducted in December 1995 by Desert Archaeology, Inc., and identified a total of 95 archaeological features. Five features are thought to be prehistoric; these include a pithouse, a possible pithouse, and three pits. A scattering of isolated Hohokam ceramics was also noted within the project area. It is probable that portions of the property were used prehistorically as fields ,with adjacent field houses. The remaining 90 features date to the American territorial and statehood periods. These include house and business foundations, wells, latrines, septic tanks, trash-filled pits, and postholes. Approximately 3 percent of the surface area of the site was explored, suggesting that many other features are present. The prehistoric features are considered possibly eligible for listing on the National Register of Historic Places under criterion D, as they have the potential to provide significant new information on Phoenix prehistory. Certain historic features are likely to be eligible under criterion D. Under criterion D, historic features containing large numbers of artifacts, fauna! bone, and ethnobotanical remains may be eligible for listing because the study of these items can provide new information on the lifestyles, health, diet, organization of space, and purchasing patterns of early Phoenicians. Desert Archaeology recommends that data recovery be conducted on selected portions of the proposed Phoenix Federal Building and United States Courthouse property to mitigate impacts resulting from construction activities. This report presents the project location and description; environmental, prehistoric, and historic background; and past archaeological work in Chapter 1. Chapter 2 contains additional archival information compiled from land records, city directories, census records, and historic maps. Chapter 3 presents the results of testing and includes descriptions of each identified feature. Chapter 4 discusses National Register eligibility issues, details possible impacts on archaeological resources, and lists research questions to guide data recovery. Chapter 5 presents a recommended work plan for data recovery. Figures are contained in Appendix A and tables in Appendix B. Appendix C details the suggested scope-of-work and timetable for additional work and a budget for the additional fieldwork, and Appendix D includes the project budget.