The Dawes Commission was organized in 1893 to accept applications for tribal enrollment between 1899 and 1907 from American Indians of the Five Civilized Tribes who resided in the Indian Territory, which later became the eastern portion of Oklahoma. The Five Civilized Tribes consist of the Cherokee, Choctaw, Creek, Seminole and Chickasaw Indians.
There are several places to get access to the Dawes rolls to see if your ancestor is listed, here are three locations.
Oklahoma Historical Society
Archives and Manuscripts Division
2100 N. Lincoln Blvd.
Oklahoma City, OK 73105