From Cheryl Shearar’s “Understanding Northwest Coast Art”:
The beaver, well known for its industriousness and building skills, is a common inhabitant throughout the Northwest Coast region. It was once widely hunted for its pelt, and knives with beaver-tooth blades were used before the introduction of iron tools.
Beaver appears in Northwest Coast mythology and is a crest in many regions. During the fur trade days, demand for beaver pelt increased as hunters depleted sea otter populations, and a Beaver crest affiliation sometimes gave individuals the right to trade in pelts.