Vanishing River Volume 2: Agricultural, Subsistence, and Environmental Studies: Part 2: Chapters 4-7

Volume 2, Part 2 provides the results of detailed research on prehistoric agricultural systems and sites in the LVAP area. Chapter 4 presents the results of SRI’s field investigations at Classic period dry-farming agricultural fields and associated field houses in an almost-300-acre area west of Horseshoe Dam. This area encompasses the hilly and gently undulating to nearly flat terrain of basalt flows, terraces, and escarpments west of the Verde River floodplain. Within this large area, 23 subsistence-related prehistoric sites have been documented during the last two decades by various institutions, including the Arizona State Museum (ASM) (Fuller et al. 1976); Arizona State University (ASU) (Rice and Bostwick 1986); Northland Research, Inc. (Dosh and Henderson 1990); and Tonto National Forest. Thirteen of these sites were investigated by SRI as part of the LVAP, though six were redefined as three loci and subsumed under the Crash Landing site, which consists of an extensive series of runoff-control and water conservation features and associated field houses at the heart of the complex. A second series of runoff-control and water conservation features was found in association with a field house at a multicomponent site containing the remains of an earlier pre-Classic period village, the Scorpion Point site. The three constituent loci of the Crash Landing site and the agricultural–field house association at the Scorpion Point site are described here. Chapter 5 presents SRI’s investigations at an isolated field house (AZ U:2:90/01-277) and three artifact scatters (AZ U:2:58/01-1149, AZ U:2:63/01-1154, and AZ U:2:91/01-279) that show evidence of low-intensity activity and ephemeral occupation. All four are located in the Horseshoe Basin in the vicinity of the Crash Landing agricultural complex (see Chapter 4). A large, low-density lithic scatter covers the entire area of the complex. These sites represent concentrations of artifacts within this broad scatter. Previous surveys suggested that sites 58/1149 and 63/1154 contained one or more field houses. LVAP investigations, however, found no evidence of intact masonry structures at either site. Chapter 6 presents the results of a field investigation documenting a sample of prehistoric agricultural sites in the LVAP area. This work entailed recording, in addition to the agricultural and field house sites mitigated in the Horseshoe Dam project area, 35 other sites in seven different study units within the lower Verde region, areas that, with few exceptions, have abundant evidence of prehistoric agricultural activity, mostly in the Horseshoe Basin and, to a lesser degree, in the Bartlett Dam area. Where possible, functional interpretations were made for different feature types, in the context of their landscape position(s). Information on architectural and other features, artifact associations, and environmental attributes (e.g., slope aspect and gradient, landform, water source, catchment size, soils, and vegetation) was also recorded. Environmental data, coupled with information about settlement locations for the sites visited, as well as all other known agricultural sites, serve as the basis for the models of dryland and irrigation agricultural and use in the LVAP that are presented in Volume 4.Chapter 7 details an agronomic study of soil productivity, water infiltrability and moisture retention, and long-term changes in soil fertility for select portions of the LVAP area. Based on the field reconnaissance and the Horseshoe Dam testing results discussed in Chapter 6, two dryland fields (Locus 78 of the Crash Landing site [78/278] and the Mullen Mesa site [AZ O:14:66/1048]) with extensive rock pile fields, rock alignments, and terraces were selected for further investigation as part of this study.