The twenty-seven notebooks that comprise this collection document Everhart's 30-plus year career as a geologist, including his work as Geologic Advisor to the U.S. Atomic Energy Commission, and subsequent work on Operation Plowshare; field work and site visits done during his years with the International Mineral and Chemical Corporation; and conference attendance.
Everhart traveled extensively during his career, and these travels are documented in his field notebooks. In the United States, Everhart visited sites in New Mexico, California, Colorado, Michigan, Utah, Florida, Wyoming, Arizona, and Arkansas; internationally, his work took him to Chile, Argentina, Spain, Japan, South Africa, Australia, Mexico, Germany, Italy, Portugal, France, and Switzerland. His notebooks document these site visits, and include observations on soil type and depth, extraction data, the mining approaches used (e.g. room and pillar, etc.), and notes from meetings held with other geologists, government employees, and mining company representatives. Everhart occasionally also includes stratigraphic sketches.
Of special interest is Everhart's 1959 field notebook (Box 2, Folder 2), in which he discusses his work on Operation Plowshare - a project to develop techniques to use nuclear explosives for peaceful construction purposes - including a visit to the Gnome test site near Carlsbad, New Mexico. Everhart visited the Gnome shot site two years in advance of detonation; his notebook documents the types of ore present (langbeinite and sylvinite), the level at which the ores are found, and extraction methods used. He also lays out the general schedule for testing at not only the Gnome site, but also the Oilshale (location not determined) and Oilsands (Athabasca, Canada) project sites.