Riverside Indian School (RIS) is a Bureau of Indian Education-operated boarding school in unincorporated Caddo County, Oklahoma, with an Anadarko address, for grades 4-12. It first opened in 1871 in Anadarko, Oklahoma. Riverside Indian School, originally known as the Wichita-Caddo School, is one of the oldest Indigenous boarding schools in the United States. There are four Indian Schools still operating today; these are Riverside Indian School, Sherman Indian High School, Chemawa Indian School, and Flandreau Indian School. Today, Riverside Indian School is home to hundreds of students that range from fourth to twelfth grade.