Muscogee (Creek) Nation  
www.muscogeenation-nsn.gov/

Cherokee Nation
http://www.cherokee.org/

Seminole Nation of Oklahoma
http://sno-nsn.gov/

The Chickasaw Nation
https://www.chickasaw.net/our-nation/contact.aspx

Choctaw Nation of Oklahoma
http://www.choctawnation.com/

The Osage Nation
https://www.osagenation-nsn.gov/

Quapaw Nation of Oklahoma
http://www.quapawtribe.com/

Pawnee Nation of Oklahoma
http://www.pawneenation.org/

Seneca-Cayuga Nation
http://sctribe.com/

Indian Health Services
http://www.ihs.gov/

American Indian Cultural Center
http://www.theamericanindiancenter.org/oklahoma-tribes