Delmer was born 7 August 1886 in Shasta, California to George Washington Johnston (1829-1909) and Harriett Ann Shelton (1862-) . He married Clara Frost .
Children
| Name | Birth | Death | Joined with |
| Orval Johnston (1910-2003) | 12 November 1910 Caldwell, Idaho | 27 May 2003 Emmett, Idaho | Noma Grace Williams (1913-2002) |
| Lela Johnston | |||