The J. Ross Clark Scrapbook dates from approximately 1897 to 1972 and consists of newspaper clippings collected by his wife, Miriam Evans Clark. The clippings relate to professional events in the lives of J. Ross Clark and his brother, Senator William A. Clark. A small number of the clippings refer to births, marriages, and deaths in Miriam Evans and J. Ross Clark's families. Also included are documents written by J. Ross Clark's grand-niece, Dorothy Murdock Dunkley, that offer additional information about the Clark and associated families.

The James Cashman Sr. Papers date from approximately 1890 to 1969 and contain correspondence, photographs, insurance records, and bank records related to Cashman and his businesses in Southern Nevada. The collection documents the lives of the Cashman family and their businesses in southern Nevada.

The Southern Nevada Historical Society Photograph Collection on Basic Magnesium, Inc. contains photographs of the construction of Basic Magnesium Inc.'s plants and buildings from 1941 to 1942. The photographs primarily depict aerial views of the plant site and various buildings, including the administration building, tent camp, chlorination buildings, electrolysis facilities, electrical distribution systems, and warehouses. The photographs also depict Lake Mead and the early buildings in Henderson, Nevada.