archaeology

The Ruby Pipeline originates in Opal, Wyoming, travels westward across Utah and Nevada, and terminates in Malin, Oregon. Almost 360 miles of the line is in Nevada, where it crosses through some of the most remote, sparsely populated land in the lower 48 states. Despite the remote nature of this corridor, it has produced a rich archaeological record reflecting a dynamic history of land-use pattern changes over a period of at least 13,000 years. Archaeological excavations were conducted at 578 prehistoric sites prior to construction of the pipeline. The sites were distributed across four ecological regions, including (from west to east): the High Rock Country, Upper Lahontan Basin, Upper Humboldt Plains, and Thousand Springs Valley. First evidence of human occupation dates to the Paleoindian (14,500-12,800 cal b.p.) and Paleoarchaic (12,800-7800 cal b.p.) periods, when people spent most of their time in the High Rock Country where important economic resources reached their highest densities. Paleoindian findings are limited to a series of Great Basin Concave Base projectile points and small obsidian flaked stone concentrations. Paleoarchaic sites are much more common, and tend to be represented by Great Basin Stemmed projectile points, bifaces, and a limited number of other flaked stone tools. Most of these assemblages reflect small groups of hunters refurbishing their tool kits as they traveled through the area. An important exception to this pattern was found at Five Mile Flat along the west end of pluvial Lake Parman where two significant habitation sites dating to 11,180 cal b.p. were discovered. One of these sites includes a house floor, which is the oldest ever found in the Great Basin. Despite the warm-dry conditions that characterized much of the middle Holocene, it appears that human populations nearly doubled during the Post-Mazama Period (7800-5700 cal b.p.). Most activity remained concentrated in the High Rock Country, but evidence for occupation begins to trickle out into the Upper Lahontan Basin and Upper Humboldt Plains regions as well. Most of the artifact assemblages remain rather narrow, often composed of Northern Side-notched and Humboldt Concave Base points, bifaces, and debitage, and reflect use of the region by mobile groups of hunters. Major changes took place with the arrival of the Early Archaic (5700-3800 cal b.p.) and continued forward into the Middle Archaic Period (3800-1300 cal b.p.). Early Archaic projectile points are largely represented by Humboldt and Gatecliff forms. It appears that population densities increased almost fourfold from the preceding interval, and all four regions experienced significant occupation for the first time. Simultaneous to this population increase and dispersal, a full complement of site types began to emerge, with large-scale residential areas becoming significant for the first time. This trend continued forward into the Middle Archaic Period where the relative frequency of residential sites almost doubled compared with the Early Archaic interval. Plant macrofossil and archaeofaunal assemblages also become more abundant and diversified at this time, probably marking a broadening of the diet breadth. This general trajectory extends into the Late Archaic (1300-600 cal b.p.) and Terminal Prehistoric periods, as people continued to expand into a wider range of habitats. This was particularly case for the latter interval, as the habitat preferences that made sense for over 12,000 years were upended, with population densities highest in the Upper Humboldt Plains and Thousand Springs Valley. This reorientation corresponds to the arrival of Numic speaking populations, especially the Western Shoshone who appear to have reached northern Nevada much earlier than the Northern Paiute, and is probably linked to a greater emphasis on small-seeded plants that are abundantly present in their territory. Although low ranked compared to many other foods, with the proper technology and work organization, small seeds could support higher population densities than was the case earlier in time. Finally, the discovery of obsidian in multiple Terminal Prehistoric sites from sources located much further away than any other time in the past may signal the earliest use of horses in northern Nevada.