Final answer:
The 'Salmon People' label for northwestern tribes is tied to cultural ceremonies and the central role of salmon fishing in their lives, also influencing social and political structures.
Step-by-step explanation:
The northwestern tribes in Talbot's reading are referred to as "Salmon People" primarily due to cultural ceremonies and their reliance on salmon fishing which is integral to their way of life. For instance, the first salmon catch is celebrated with ceremonial practices such as those by the Takelma peoples of the Rogue River Valley in Oregon. These ceremonial practices highlight the importance of salmon as a resource and symbolize the tribes' commitment to environmental stewardship. Additionally, the political and social structures of these tribes are closely linked with salmon, as can be seen in clan names like the raven, salmon, eagle, and killer whale, and the role of salmon in supporting a dense population due to the resource-rich environment.