In 1889, the U.S. government forced tribes to cede the western half of the Indian Territoryto white settlers via Land Runs. Beginning in 1890, territorial counties were created to pave the way to statehood on November 16, 1907.
Current Counties | Territorial Counties | Indian Territories
| County | Comments |
| A | "A County" was the original designation for Lincoln County, Oklahoma Territory. It included some of the former Absentee Shawnee, Iowa, Kickapoo, and Sac & Fox Lands administered by the Sac & Fox Agency. |
| B | "B County" was the original designation for Pottawatomie County, Oklahoma Territory. It included some of the former Absentee Shawnee, Kickapoo, and Pottawatomie Lands administered by the Sac & Fox Agency. | Beaver | One of the original seven counties of Oklahoma Territory, outlined and designated by numbers. Beaver was the Seventh, and covered what had earlier been designated as No Man's Land. At statehood, it was broken up into Cimarron, Texas, and Beaver Counties. |
| C | "C County" was the original designation for Blaine County, Oklahoma Territory |
| D | "D County" was the original designation for Dewey County, Oklahoma Territory |
| Day | Day County in Oklahoma Territory, was abolished at statehood, comprising the northern portion of Roger Mills County and the southern portion of Ellis County. Named for William R. Day |
| E | "E County" was the original designation for Day County, Oklahoma Territory |
| F | "F County" was the original designation for Roger Mills County, Oklahoma Territory. |
| G | "G County" was the original designation for Custer County, Oklahoma Territory. |
| H | "H County" was the original designation for Washita County, Oklahoma Territory. |
| I | "I County" was the original designation for Caddo County, Oklahoma Territory |
| K | "K County" was the original designation for Kay County, Oklahoma Territory |
| L | "L County" was the original designation for Grant County, Oklahoma Territory. |
| M | "M County" was the original designation for Woods County, Oklahoma Territory. |
| N | "N County" was the original designation for Woodward County, Oklahoma Territory. |
| O | "O County" was the original designation for Garfield County, Oklahoma Territory. |
| P | "P County" was the original designation for Noble County, Oklahoma Territory. |
| Q | "Q County" was the original designation for Pawnee County, Oklahoma Territory. |
Page updated:
State Coordinator: Linda K. Lewis
Asst State Coordinator: Rebecca Maloney
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