The Hanna Formation is a geologic formation in Wyoming. It preserves fossils dating back to the Torrejonian to Tiffanian stages of the Paleogene period.^[1]

• List of fossiliferous stratigraphic units in Wyoming
• Paleontology in Wyoming

• C. S. Scott and R. C. Fox. 2005. Windows on the evolution of Picrodus (Plesiadapiformes: Primates): morphology and relationships of a species complex from the Paleocene of Alberta. Journal of Paleontology 79(4):635-657
• R. Secord. 1998. Paleocene mammalian biostratigraphy of the Carbon Basin, southeastern Wyoming, and age constraints on local phases of tectonism. Rocky Mountain Geology 33(1):119-154
• J. A. Lillegraven. 1994. Age of upper reaches of Hanna Formation, northern Hanna Basin, south-central Wyoming. Berliner geowissenschaftliche Abhandlungen E (Paläobiologie) 13:203-219