The Stratigraphy and Fauna of the Hackberry Stage of the Upper Devonian by Carroll Lane Fenton and Mildred Adams Fenton, provides a comprehensive analysis of the rock formations and abundant, well-preserved fossil fauna found in the Hackberry stage in north central Iowa. Despite its limited geographic and stratigraphic presence, the Hackberry stage offers a wealth of species, many of which have been either previously misidentified or undescribed. This work aims to detail the strata and discuss the fauna, including typical, rare species, and the evolutionary and associative aspects in certain cases. Though some groups (such as Protozoa and Stromatoporoidea) remain undescribed due to time constraints, the text introduces essential terminologies and classifications used in stratigraphy and paleontology. The authors acknowledge significant contributions from various colleagues and collectors, enhancing the study's depth and accuracy.