Which method did the native americans of the pacific northwest rely on for their food?

Fishing.

The indigenous peoples of the Pacific Northwest Coast were the groups that resided along the coast of British Columbia, Washington State, parts of Alaska, Oregon and northern California. They were composed of many nations and tribes, such as the Coast Salish and the Chinook.

The Pacific Northwest Coast was rich in natural resources and enjoyed mild weather, allowing dense populations to arise. While they were all very different, one trait they shared was their reliance on fishing and the central role of salmon in their culture.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.