APA (7th ed.) Citation

United States. Bureau of Reclamation. Great Plains Region. (1989). Great Plains region information map. The Region.

Chicago Style (17th ed.) Citation

United States. Bureau of Reclamation. Great Plains Region. Great Plains Region Information Map. Billings, Mont.: The Region, 1989.

MLA (9th ed.) Citation

United States. Bureau of Reclamation. Great Plains Region. Great Plains Region Information Map. The Region, 1989.