The project director was Terry Abraham, Head, Special Collections at the University of Idaho Library. During 1987/1988, Herman Ronnenberg served as project director. Appraisal, arrangement, and description were begun by Richard C. Davis as project archivist from the end of 1986 into 1989 and carried on by Michael Tarabulski as project archivist in 1991-1992. Among those who worked on the two projects were Doug Carr, Gregory Eisenlein, Harriet Essiam, Susan Hamlin, Jennifer Jenness, Lena Johnson, Dana Miller, Dixie Miller, Judith Nielsen, Kelly Clark O'Brien, Marilyn Sandmeyer, Leslie Smallwood, Clay Williams, and Wilma M. Woods. Advice and comments on the appraisal of mining records were received from Earl H. Bennett, Francis X. Blouin, Jr., Maynard Brichford, William S. Greever, Michael Ostrogorsky, Duane A. Smith, Clark C. Spence, and Glenn Vent. A guide to the records has been published as Day to Day: A Guide to the Records of the Historic Day Mines Group in the University of Idaho Library; edited by Terry Abraham and Richard C. Davis; Moscow: University of Idaho Library, 1992.

The Day Mines collection deposited in the University of Idaho Library is organized into seventy-three manuscript groups and includes the records of over eighty corporations or mining partnerships acquired by, merged with, or established by the Days, or in which the Days at some time held a dominant interest. Each group documents one or more variations on the means of organizing capital and labor for the exploitation of mineral wealth. The corporate records relate to a variety of economic, social, and political topics, such as air and water pollution, the life of the working man, taxation, social welfare, and business organization and capitalization, as well as to the more specific aspects of mineral land acquisition, mine development, mine and smelter technology, metal marketing and the relations between mines and smelter companies from the 1890s into the 1980s. However, there is little related to the Coeur d'Alene mining wars of the 1890s.