The one caveat on that is it adresses slavery among Alaskan Natives and First Nations peoples in BC who are not Native Americans per this article title Those enslaved by the Tlingit and Haida and Nuu chah nulth and Kwakwaka wakw were often enough Coast Salish Native American peoples in the Puget Sound region however and I think the book also discusses slavery of neighbouring groups such as the Chehalis by the Chinookan peoples