Fish Remains from Nahas Cave: Archaeological Evidence of Anadromous Fishes in Southwestern Idaho

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)