1890-1906 The Organic Act of 1890 established Oklahoma Territory. This act organized 7 counties into the "Unassigned Lands" and the Oklahoma panhandle("No Man's Land) and provided for the organization of additional counties as Indian Governments were discontinued and surplus land was opened to settlers. During this time, the Oklahoma territory expanded to fill western Oklahoma by gradually absorbing the following area: Reservations Central Oklahoma1891 Cheyenne and Arapaho land1892 Cherokee outlet1893 Greer County1896 Comanche, Kiowa and Apache land 1901 and 1906 The eastern portion remained as Indian territory. So, where was Jefferson County in 1900? These are the Counties from the census . Beaver Greer Payne Blaine Kay Washita Logan Wichita Kiowa Comanche Grant Pawnee Garfield Osage and Kew Dewey Oklahoma Noble Woodward Pottawatomie Canadian Kingfisher Clevland Custer Dawn