The United States ratified the Charter of the Organization of American States and is an OAS member. The United States signed, but did not ratify, the American Convention on Human Rights.
American Convention on Human Rights (@ Organization of American States)
American Declaration on the Rights and Duties of Man (@ Organization of American States)
American Declaration on the Rights of Indigenous Peoples (@ Organization of American States)
Indigenous Peoples topic page (@ Organization of American States)
Rapporteurship on the Rights of Indigenous Peoples (@ Inter-American Commission on Human Rights)
OAS > IACHR > Rapporteurships > Rights of Indigenous Peoples > Reports on Petitions and Cases
Below are links to materials on the land claim case filed by the Onondaga Nation and the Haudenosaunee Confederation with the Inter-American Commission on Human Rights. The Commission admitted the petition based on Article II (equality before the law) and Article XVIII (right to fair trial/judicial protection) of the American Declaration on the Rights and Duties of Man.
See also these brief overviews: