"Under the Indian Arts and Crafts Act of 1990, any item sold as Indian or Native American must be made by an individual who is a member of a state or federally recognized Indian tribe or tribally certified as an Indian artisan; works identified by tribe must be made by a member or certified artisan from that tribe." This I'm quoting from the "Native American Art and The Law: A collector's Guide" published by The ATADA Foundation, Inc. (Antique Tribal Art Dealers Association)
For those of you that deal in such items, I would recommend visiting their web site, www.atada.org, for information regarding the laws dealing such items. There is information concerning things like the American Antiquities Act of 1906 as well as laws and treaties involving endangered species. Much of this info is a must have for those wishing to deal in Native American Arts & Crafts and avoid any inadvertent legal problems.
Link to US Dept of the Interior: Arts & Crafts Board