Baja Oklahoma

“Baja Oklahoma” (lower Oklahoma) is an Oklahoma nickname for the state of Texas. The term is similar to Baja California. “Baja Oklahoma” is a gentle insult and is not normally used by Texans, although it was the title of a Dan Jenkins novel and film (1988).
 
 
Wikipedia: Baja California
Baja California (literally “lower California” in Spanish) is the northernmost state of Mexico. It is considered territory of Northern America. It is sometimes informally referred to as Baja California Norte, to distinguish it from both the Baja California peninsula, of which it forms the northern half, and Baja California Sur, the adjacent state that covers the southern half of the peninsula. Before becoming a state in 1953, the area was known as the North Territory of Baja California. It has an area of 71,576 km² (about 27,600 mi², or 3.57% of the land mass of Mexico. The state is bordered on the west by the Pacific Ocean, on the east by Sonora, the U.S. State of Arizona, and the Sea of Cortez or Gulf of California, and on the south by Baja California Sur. Its northern limit is the U.S.-Mexico border, adjacent to the U.S. state of California.   
 
Internet Movie Database
Plot summary for
Baja Oklahoma (1988) (TV)
Dan Jenkins co-wrote the screenplay based on his novel of the same name about Juanita, a barmaid in Ft. Worth, Texas, who wants to be a country-western songwriter.
 
16 December 1955, Long Beach (CA) Independent, pg. 2, col. 1:
A red-haired congressman from Baja Oklahoma—sometimes known as Texas—was about ready Thursday to challenge Sen. Arthur V. Watkins (R-Utah) to a game of Rio Grande roulette—Colt .45 Peacemakers at six paces.
 
20 September 1956, Oakland (CA) Tribune, “Sooners ‘Raid’ Texas Schools,” pg. 38, col. 1:
When it comes to football the new name for the great state of Texas is Baja Oklahoma.
 
14 December 1958, Long Beach (CA) Independent-Press-Telegram, pg. B12:
The real lift to the morale of the citizens of the former Lone Star State (if subdivided—ed.) would come from a more equitable distribution of the inferior weather, which has been pretty well monopolized by that section popularly known as “Baja Oklahoma.”
 
4 January 1960, Pasadena (CA) Star-News, comics:
TELL ME, MY LITTLE “YELLAH ROSE,” IS IT TRUE, NOW THAT IT ISN’T THE BIGGEST STATE, THAT TEXAS IS KNOWN AS BAJA OKLAHOMA?
 
21 October 1972, Dallas Morning News, Tolbert’s Texas by Frank X. Tolbert, section A, pg. 23:
“We’ll make Texas a kind of sub-state or junior province,” said my Okie friend, “and we’ll call it Baja Oklahoma.”
 
13 January 1974, Cedar Rapids (Iowa) Gazette, pg. D1, col. 1:
This will be the first Super Bowl in the state of Texas, and maybe that helps even the National Football league think big. We’ve been needling our Texas hosts a bit. You know, calling Texas “Baja Oklahoma” and suggesting that old gag that there wouldn’t even be a Texas if there had been a back door at the Alamo.

30 March 1979, Placerville (CA) Mountain Democrat, pg. A5, col. 1:
Sheriff run ‘em outta Arkansas in the 1800s; and, the Rangers run ‘em outta Baja Oklahoma (that there’s North Texas) long about the turn of the century.

12 April 1991, Placerville (CA) Mountain Democrat, pg. A13, col. 1:
It runs from the outskirts of Oklahoma City to the border of Baja, Oklahoma (as Oklahomans call Texas).