Oklahoma Maps
One of the best books of maps for Oklahoma is John Wesley Morris, Charles R. Goins, and Edwin C. McReynolds, Historical Atlas of Oklahoma, 3rd ed. Norman, Oklahoma: University of Oklahoma Press, 1986. (FHL book 976.6 E3m 1986; 1965 edition on film 1,000,357 item 3.)
The University of Oklahoma and Oklahoma State University have large collections of maps and atlases.
The Family History Library has several maps, including some of the Indian Territory.
Web Sites