Update. Thanks to information posted by Nancy Mumford and Sheryl McClure on other forums it seems fairly sure that Frank's parents were Francis C. Yerkes (1856? - bef 1900) from Indiana and Mary E. Scherer (Sep 1859 - ?) from Illinois. Francis, who clerked in a drygoods store in Junction City, Kansas (ten miles east of Chapman), died before 1900. He was the son of Jonathan Yerkes from Pennsylvania. Young Frank had an elder sister, Beta (sometimes Bettie), born Jun 1879.