This collection consists of one handwritten notebook. The notebook contains a numbered list of plant and tree specimens Leiberg collected in Oregon, with notes as to date (month only given, June–September), locations and altitudes. Although no year is given, it is likely that the notes were compiled during the summer of either 1895 or 1896, when Leiberg worked in Oregon for the United States Department of Agriculture (USDA). This list is a duplicate of one first believed lost in the mail between Athol, Idaho and the USDA in Washington, D.C., but the original was later found.