Why did Northwest Coast Indian families move among several sites during summer?

Northwest Coast Indian families moved among several sites during the summer primarily to maximize the efficiency of their food procurement. Because natural resources were unevenly distributed across the landscape and available only at specific times, it was most effective for house groups to maintain multiple bases of operation.1

During the summer, these groups dispersed into smaller units to travel between various fishing and berry-picking locations as these resources became available. This seasonal movement was essential because summer was a period of intense labor, during which food had to be caught, gathered, and processed to ensure a sufficient supply for the winter months. By utilizing different sites, families could exploit the region's diverse aquatic and terrestrial resources, such as spawning fish and seasonal berries, which were critical for their subsistence.1