Justice Amos McNac is a resident of Bristow, Oklahoma. He attended Olive Public School, Technical School in Amarillo, Texas and Washburn University in Topeka, Kansas.

The Courts of the Muscogee (Creek) Nation are required to apply the traditions and customs of the Muscogee people in its judicial determinations. As a member of the Muscogee (Creek) Nation Supreme Court, Justice McNac brings an understanding of the traditional customary law of the Muscogee and Yuchi people, providing an invaluable resource for the Court in matters concerning customs, traditions, and key concepts of native law. Justice McNac believes a judge must have knowledge of the complex, elaborate kinship and clans of those who have come before.

Justice McNac has served as special counselor for the District Court in hearings concerning a tribal town dispute, which was conducted in our native language. He has been active in Indian causes, Indian tradition and Indian justice. He has supported the rights of the native people to use the religious symbols and to practice and participate in traditional ceremonies and rituals. He was an active participant in the Harjo v. Kleppe Civil Action 74-189, 420 F. Supp. 110 (D.D.C. 1976) lawsuit and was instrumental in the development of the 1979 Constitution, including an explanation of the Constitution to traditional citizens in Mvskoke throughout the Nation.

Justice McNac reads, writes and speaks the Mvskoke language. He has played an instrumental role in helping the Muscogee (Creek) Nation develop the new language revitalization program and the curriculum for the language classes at the College of the Muscogee (Creek) Nation. Justice McNac has served on the Language Program, Language Preservation and Language Revitalization Committees in its efforts to keep the Mvskoke Language a vital part of our culture. He was a faculty member and panelist on the Preservation of Native American Languages panel for the Sovereignty Symposium XI. Additionally, Justice McNac has participated in Tribal College Study Groups and the Tribal Project Standing Committee, where he served as chair, to help with the development of the Tribal College’s curriculum and accreditation. Since 2004, Justice McNac has served as an adjunct professor, teaching the Mvskoke language. Always instrumental in the preservation of the Mvskoke culture, Justice McNac provides valuable traditional and cultural information to many programs throughout the Nation, ensuring our buildings and program reflect as much of the Creek heritage as possible. Justice McNac served in the United States Air Force from 1963 to 1967 and is a member of the Veterans of Foreign Wars. He is a member of the Native American Bar Association, the American Bar Association and the National American Indian Court Judges Association and charter member of the Oklahoma Indian Judges Association.

Justice McNac has served four terms as Justice on the Supreme Court, from 1992 to 2010 and from 2017 to present. He has served as Chief Justice for the 1997 and 2003 calendar years, and as Vice-Chief Justice for the 1994, 2002, and 2020-2023 calendar years.