PO | County | Dates | Comments |
| KAINTUCK | Madison | 1889-1893 | was REXBURG |
| renamed REXBURG | |||
| KAMAI | Lewis | 1878-1879 | |
| KAMIAH | Lewis | 1894-Date | |
| KANOKA | Gooding | 1897-1905 | was BRIGGS |
| renamed CLEARLAKE | |||
| KAUFMAN | Fremont | 1899-1915 | |
| KEENAN CITY | Bonneville | 1874-1875 | |
| KEEVER | Bingham | 1916-1918 | renamed MORELAND |
| KELLOGG | Shoshone | 1887-Date | |
| KELSO | Cassia | 1880-1885 | |
| KENDRICK | Latah | 1890-Date | was LATAH |
| KENNEY | Boundary | 1914-1915 | |
| KENYON | Cassia | 1911-1918 | |
| 1919-1919 | |||
| KETCHUM | Blaine | 1880-Date | |
| KEUTERVILLE | Idaho | 1888-1964 | |
| KIDDER | Idaho | 1904-1910 | |
| KILGORE | Clark | 1889-1963 | |
| KIMAMA | Lincoln | 1886-1887 | |
| 1901-1932 | |||
| KIMBERLY | Twin Falls | 1905-Date | |
| KING | Caribou | 1894-1899 | |
| KING HILL | Elmore | 1908-1992 | now CPO |
| KINGSTON | Shoshone | 1885-Date | |
| KIPPEN | Lewis | 1896-1909 | |
| KLOCKMAN | Boundary | 1916-1930 | |
| KNOTT | Idaho | 1903-1909 | |
| KNOX | Valley | 1904-1908 | |
| KOOSKIA | Idaho | 1890-1902 | renamed LORENA |
| 1902-Date | was STUART | ||
| KOOTENAI | Bonner | 1885-1895 | |
| 1895-1903 | renamed BOYER | ||
| 1904-1963 | now CPO | ||
| KRAMER | Adams | 1907-1909 | |
| KUNA | Ada | 1884-1887 | was OWYHEE |
| 1905-Date | |||
| KUPRO | Idaho | 1903-1912 | was LORENA |
Contributed 2021 Oct 05 by Mark Metkin
Copyright © 1996 - The USGenWeb® Project, IDGenWeb