Prairie Bull Snake (Pituophis sayi: Cooper, James G., George Suckley, William Cooper, George Gibbs, Asa Gray, and John L. Le Conte. 1859. The natural history of Washington territory, with much relating to Minnesota, Nebraska, Kansas, Oregon, and California, between the thirty-sixth and forty-ninth parallels of latitude, being those parts of the final reports on the survey of the Northern Pacific railroad route, containing the climate and physical geography, with full catalogues and descriptions of the plants and animals collected from 1853 to 1857. Bailliere Bros., London, H. Bailliere;, New York, New York. pp.); Oregon Bull Snake (Pituophis wilkesii: Cooper, James G., George Suckley, William Cooper, George Gibbs, Asa Gray, and John L. Le Conte. 1859. The natural history of Washington territory, with much relating to Minnesota, Nebraska, Kansas, Oregon, and California, between the thirty-sixth and forty-ninth parallels of latitude, being those parts of the final reports on the survey of the Northern Pacific railroad route, containing the climate and physical geography, with full catalogues and descriptions of the plants and animals collected from 1853 to 1857. Bailliere Bros., London, H. Bailliere;, New York, New York. pp.); Bellona Bull Snake (Pituophis bellona: Cooper, James G. 1869. The fauna of California and its geographical distribution. Proceedings of the California Academy of Sciences 4():61-81); Churchill's Bull-snake (Pituophis bellona: Cooper, James G. 1869. The naturalist in California. The American Naturalist 3(9):470-481); Bull Snake (Pityophis sayi bellona: Coues, Elliott. 1875. Synopsis of the reptiles and batrachians of Arizona with critical and field notes, and an extensive synonymy. Report upon Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian. Volume 5. ():585-633); Adder (Pityophis sayi bellona: Coues, Elliott. 1875. Synopsis of the reptiles and batrachians of Arizona with critical and field notes, and an extensive synonymy. Report upon Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian. Volume 5. ():585-633); Western Pine Snake (Pityophis sayi: Jordan, David Starr. 1876. Manual of the Vertebrates of the Northern United States: Including the District East of the Mississippi River, and North of North Carolina and Tennessee, Exclusive of Marine Species. Jansen, McClurg, and Company, Chicago, Illinois.. 342pp.); Bull Snake (Pityophis sayi bellona: Yarrow, Henry C. 1876. List of Skeletons and Crania in the Section of Comparative Anatomy of the United States Army Medical Museum for use during the International Exhibition of 1876 in Connection with the Representation of the Medical Department U.S. Army. Army Medical Museum, Washington, D. C. pp.); Gopher Snake (Pityophis sayi mexicanus: Yarrow, Henry C. 1876. List of Skeletons and Crania in the Section of Comparative Anatomy of the United States Army Medical Museum for use during the International Exhibition of 1876 in Connection with the Representation of the Medical Department U.S. Army. Army Medical Museum, Washington, D. C. pp.); Western Pine Snake (Pityophis sayi: Jordan, David S. 1878. Manual of the Vertebrates of the Northern United States: Including the District East of the Mississippi River, and North of North Carolina and Tennessee, Exclusive of Marine Species. Second Edition, Revised, and Enlarged. Jansen, McClurg & Company, Chicago. pp.); Western Bull Snake (Pityophis sayi bellona: Yarrow, Henry C. 1882. Check list of North American Reptilia and Batrachia with catalogue of specimens in U. S. National Museum. Bulletin of the United States National Museum (24):1-249); Say's Pine Snake (Pityophis sayi sayi: Yarrow, Henry C. 1882. Check list of North American Reptilia and Batrachia with catalogue of specimens in U. S. National Museum. Bulletin of the United States National Museum (24):1-249); Western Pine Snake (Pityophis sayi sayi: Davis, N. S., and Frank L. Rice. 1883. List of Batrachia and Reptilia of Illinois. Bulletin of the Chicago Academy of Sciences 1(3):25–32); Western Bull Snake (Pituophis sayi: Hay, Oliver P. 1892. Batrachians and Reptiles of the State of Indiana. Pages 409-624 in 17th Annual Report of the Indiana Department of Geology and Natural Resources, William B. Burford, Printer and Binder, Indianapolis, Indiana. pp.); Say's Pine Snake (Pituophis sayi: Hay, Oliver P. 1892. Batrachians and Reptiles of the State of Indiana. Pages 409-624 in 17th Annual Report of the Indiana Department of Geology and Natural Resources, William B. Burford, Printer and Binder, Indianapolis, Indiana. pp.); Bull Snake (Pityophis catenifer: Garman, H. 1892. A synopsis of the reptiles and amphibians of Illinois. Illinois Laboratory of Natural History Bulletin 3():215-403); Bull Snake (Pituophis catenifer: Rhoads, Samuel N. 1895. Contributions to the zoology of Tennessee. No. 1, Reptiles and amphibians. Proceedings of the Academy of Natural Sciences, Philadelphia 47():376-407); Western Gopher Snake (Pituophis catenifer: Van Denburgh, John. 1897. The reptiles of the Pacific Coast and Great Basin: An account of the species known to inhabit California, and Oregon, Washington, Idaho, and Nevada. Occasional Papers of the California Academy of Sciences 5():9-236); Desert Gopher Snake (Pituopohis catenifer deserticola: Van Denburgh, John. 1897. The reptiles of the Pacific Coast and Great Basin: An account of the species known to inhabit California, and Oregon, Washington, Idaho, and Nevada. Occasional Papers of the California Academy of Sciences 5():9-236); California Pine Snake (Pityophis catenifer catenifer: Brown, Arthur, E. 1902. Report of the Board of Directors. Pages 5-22 in Thirtieth Annual Report of the Board of Directors of the Zoological Society of Philadelphia. Allen, Lane, and Scott, Philadelphia, Pennsylvania. pp.); Say's Bull Snake (Pityophis catenifer sayi: Brown, Arthur, E. 1902. Report of the Board of Directors. Pages 5-22 in Thirtieth Annual Report of the Board of Directors of the Zoological Society of Philadelphia. Allen, Lane, and Scott, Philadelphia, Pennsylvania. pp.); Bull Snake (Pituophis sayi: Hurter, Julius. 1911. Herpetology of Missouri. Transactions of the Academy of Science St. Louis 20(5):59-274); Western Bull Snake (Pituophis sayi: Hurter, Julius. 1911. Herpetology of Missouri. Transactions of the Academy of Science St. Louis 20(5):59-274); Pine Snake (Pituophis sayi: Hurter, Julius. 1911. Herpetology of Missouri. Transactions of the Academy of Science St. Louis 20(5):59-274); Western Bull-snake (Pituophis catenifer catenifer: Stejneger, Leonard and Thomas Barbour. 1917. A Checklist of North American Amphibians and Reptiles. Harvard University Press, Cambridge, Massachusetts. pp.); Bull-snake (Pituophis sayi: Stejneger, Leonard and Thomas Barbour. 1917. A Checklist of North American Amphibians and Reptiles. Harvard University Press, Cambridge, Massachusetts. pp.); Bull Snake (Pituophis sayi: Strecker, John K. 1922. An annotated catalogue of the amphibians and reptiles of Bexar County, Texas. Bulletin Scientific Society of San Antonio (4):1-31); San Diegan Gopher Snake (Pituopohis catenifer annectens: Van Denburgh, John. 1922. The Reptiles of Western North America: An Account of the Species Known to Inhabit California and Oregon, Washinton, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora, and Lower California. Volume I. Lizards. California Academy of Sciences, San Francisco. 556pp.); Coast Gopher Snake (Pituopohis catenifer catenifer: Van Denburgh, John. 1922. The Reptiles of Western North America: An Account of the Species Known to Inhabit California and Oregon, Washinton, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora, and Lower California. Volume I. Lizards. California Academy of Sciences, San Francisco. 556pp.); Valley Gopher Snake (Pituopohis catenifer hermanni: Van Denburgh, John. 1922. The Reptiles of Western North America: An Account of the Species Known to Inhabit California and Oregon, Washinton, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora, and Lower California. Volume I. Lizards. California Academy of Sciences, San Francisco. 556pp.); Utah Gopher Snake (Pituopohis catenifer rutilus: Van Denburgh, John. 1922. The Reptiles of Western North America: An Account of the Species Known to Inhabit California and Oregon, Washinton, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora, and Lower California. Volume I. Lizards. California Academy of Sciences, San Francisco. 556pp.); Gopher Snake (Pituophis catenifer: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); San Diegan Gopher Snake (Pituophis catenifer annectans: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Pacific Gopher Snake (Pituophis catenifer catenfier: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Great Basin Gopher Snake (Pituophis catenifer deserticola: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Bull Snake (Pituophis sayi: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Arizona Bull Snake (Pituophis sayi affinis: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Common Bull Snake (Pituophis sayi sayi: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Pacific Bull Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Arizona Bull Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Arizona Gopher Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Eastern Bull Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Prairie Bull Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Bull Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Blow Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Adder (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Southern Bull Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Gopher Snake (Pituophis catenifer affinis: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Coast Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Churchill's Bull Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Great Basin Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Pine Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Pacific Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Adder (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Pacific Pine Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Yellow Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Coastal Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Pacific Bull Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Gopher Snake (Pituophis catenifer catenifer: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Gopher Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Arizona Bull Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Desert Gopher (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Desert Gopher Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Bull Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Southern Bull Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Utah Blow Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Desert Bull Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Great Basin Blow Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Great Basin Gopher Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Blow Snake (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Adder (Pituophis catenifer deserticola: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Say's Bull Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Yellow Gopher (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Speckled Chain Adder (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Speckled Adder (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Prairie Bull Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Eastern Bull Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Gopher Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Yellow Gopher Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Spotted Bull Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Pine Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Say's Pine Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Western Bull Snake (Pituophis catenifer sayi: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Bull Snake (Pituophis catenifer: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); Gopher Snake (Pituophis catenifer: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); Sonoran Gopher Snake (Pituophis catenifer affinis: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); San Diego Gopher Snake (Pituophis catenifer annectens: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); Pacific Gopher Snake (Pituophis catenifer catenifer: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); Great Basin Gopher Snake (Pituophis catenifer deserticola: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); Santa Cruz Island Gopher Snake (Pituophis catenifer pumilus: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.); Bull Snake (Pituophis catenifer sayi: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.);