Box four contains research related to the Plains Village era site, Steed-Kisker. Since ties to Cahokia were theorized, some tie-in for Cahokia materials is possible within the materials. Given that this site is located near Kansas City, other research materials that pertain to that locality are also housed in box four, including a manuscript of a paper on Mississippian Developments in the Kansas City Locality, infrared aerial photographs of the area, and other broader topics such as Mississippian pottery and Missourian archaeology sites. Box four also includes materials related to the Mesoamerica series.

Box six contains materials related to the Cahokia site that include notes related to Cahokia architecture and excavations. Box six also contains materials related to the Prehistoric Native Americans of the Great Plains, Mesoamerica, and the Pawnee & Wichita series.

Box seven contains materials related to research done on Native American sacred sites. Specifically, topics include Pawnee cosmology, animal lodges (and animals in general tribal contexts), and other symbolism and mythology within native tribes. Animal lodge research was conducted in a number of states including Kansas, Nebraska, South Dakota, Wyoming, and Oklahoma. Much of the materials related to this topic include corresponding slides and give further context to said slides.

Box eight includes a continuation of research materials related to Native American sacred sites. Specifically included here is research on hot springs sites in Kansas, Oklahoma, and Wyoming. Materials in box eight also correspond to slides (both North American and European) and provide further context for said slides.

Box one contains various biographical information, including photographs of Pat O'Brien and Donna Roper and copies of Pat's CV and obituary. Contents also include miscellaneous newspaper articles and correspondence that are not associated with a dedicated project or research area, award nominations, and society/commission materials from Professional Archaeologists of Kansas (PAK), Iowa Archaeological Society, Kansas Antiquities Commission, Sigma Xi, Ellis Island Centennial Commission, and Plains Anthropological Society. Other materials include a collection of conference booklets and abstracts from the American Indian Workshop, Flint Hills Conference, and Plains Anthropological Conference (1969-2002).