ATNI Conventions are where members convene for discussion, presentations and the work of the committees in regard to policy, legislation, and the future of Indian Country in the Northwest.

ATNI has taken as its purpose to: provide a forum for sharing information on matters of interest to its member Tribes, develop consensus on matters of mutual importance, assist member Tribes in their governmental and programmatic development consistent with their goals for self-determination and self-sufficiency and provide for effective public relations and education program with the non-Indian communities. Through its conventions, forums, networks and alliances, it is the intent of ATNI to represent and advocate for the interests of its member Tribes to national Indian and non-Indian organizations and governments.