We have very carefully researched our Columbia River and Alaskan trade beads. At least to the extent that we could. Our beads have been looked at by leading experts and passed muster. We have traveled extensively in the Pacific Northwest and Alaska visiting with Native American peoples, visiting their Cultural Centers, making sure that the beads we see can validate the beads we hold. We have also visited private museums in the Northwest cross checking their beads with ours. One of the best museums with dozens of colored plates of beads traded in the Northwest and Alaska is: The Burke Museum at the University of Washington at Seattle. Below is a link to the Burke Museum on line visitors center. When you open this page click on "ethnology" department. Be prepared to view approximately 50 pages of beads, etc. http://www.washington.edu/burkemuseum/collections/index.php