The anadromous fish runs of the Snake and Owyhee rivers and their tributaries have provided an important element of interpretations of native subsistence in southwestern Idaho (see Butler 1978:30-31; Pavesic 1978; Swanson 1965). Prior to the development of major water control systems in the Northwest, anadromous fishes migrated as far east in the Snake River as Shoshone Falls, located adjacent to the present city of Twin Falls, Idaho, and into the Owyhee River (Evermann 1896, 1897; see also Steward 1938:165-168). Further accounts suggest that some anadromous fishes found their way into the Bruneau River west of Shoshone Falls (Gilbert and Evermann 1894) and into the Jarbidge River, a primary tributary of the Bruneau, by which they entered Nevada (La Rivers and Trelease 1952:113) (see Fig. 1). Steward (1938:167-168) reported two major spring salmon runs and a fall salmon run of lesser magnitude. The first salmon run, referred to as tahma agai or spring salmon, occurred during March or April and probably consisted of the salmon or Steelhead Trout, Salmo gairdnerii. While belonging to the family Salmonidae, these fish are not true salmon (see Casteel 1976: 89). A late spring run occurred in May or June and consisted of the Chinook Salmon Oncorhynchus tshawytscha, locally named taza agai or summer salmon (Steward 1938:167).

The presence of anadromous fish resources in southwestern Idaho provides a major basis for archaeological interpretations of the prehistory of the western Snake River area (see Butler 1978; Favesic 1978; Swanson 1965). These interpretations are based on ethnographic accounts (e.g.. Steward 1938; Liljeblad 1957; Murphy and Murphy 1960) portraying spring/summer and fall salmon runs as the focal point of an otherwise transhumant pattern emphasizing unspecialized plant resource use. Salmonid resources in southern Idaho in this context have been viewed equal to other regionally important Great Basin resources such as pinon (Favesic 1978). Clearly, as indicated by fish weirs along the Middle Snake River (Meatte 1982, 1983; Butler 1983), native populations invested considerable energy in exploitation of fish resources. This emphasis, however, stands in contrast to ethnohistoric accounts of Snake River Shoshoni (Fremont 1887; Steward 1938) who depended heavily on supplies of stored salmon during the winter months. These accounts describe starving aboriginal groups awaiting the first spring salmon, a situation inconsistent with the magnitude of the resource and its ethnohistorically documented exploitation. This raises questions regarding the nutritional value of the resource. The purpose of this paper is to evaluate the food potential of salmon for native populations by examining an historic fisheries harvest, calculating its food potential and assessing variables affecting loss of nutritional value.

This report is a compilation of known radiocarbon dates reported from archaeological sites in southern Idaho. Its purpose is to provide an inventory of previously published and unpublished dates to facilitate use by researchers and cultural resource managers. Contemporary professional demands have created a surge of antiquities management and assessment studies which are quickly outpacing traditional research reports. Management decisions often rely on outdated chronologies which have not been critically evaluated. In addition, many radiocarbon dates are not readily available to scholars working in Idaho and adjacent areas. As systematic archaeological studies continue in Idaho, the need for usable research tools has increased (e.g., Pavesic, Plew, and Sprague 1979). The report attempts to expand the base of current archaeological interpretation and analysis. While the report does not evaluate individual published dates (e.g., Arundale 1981), it does provide an initial step toward reevaluation of the chronologies of the Upper Snake and Salmon River Country (Butler 1978) and forms a basis for generating chronologies for such areas as Southwestern Idaho (Plew, Pavesic, and Green n.d.).