On a simple east/west basis, Western Oklahoma is popularly considered that part of the state west of

I-35 Interstate 35 (I-35) is a major Interstate Highway in the central United States. As with most primary Interstates that end in a five, it is a major cross-country, north–south route. It stretches from Laredo, Texas, near the Mexican border ...

. I-35 creates a north/south line through the approximate center of the main body of the state (i.e., without regard for the

Oklahoma Panhandle The Oklahoma Panhandle (formerly called No Man's Land, the Public Land Strip, the Neutral Strip, or Cimarron Territory) is a salient in the extreme northwestern region of the U.S. state of Oklahoma, consisting of Cimarron County, Texas Count ...

), passing through

Oklahoma City Oklahoma City (), officially the City of Oklahoma City, and often shortened to OKC, is the capital and largest city of the U.S. state of Oklahoma. The county seat of Oklahoma County, it ranks 20th among United States cities in population, a ...

, the state capital. However, other definitions are possible. For tourism purposes, the Oklahoma Tourism and Recreation Department breaks the state into six regions. The 14 counties of

Southwest Oklahoma Southwest Oklahoma is a geographical name for the southwest portion of the state of Oklahoma, typically considered to be south of the Canadian River, extending eastward from the Texas border to a line roughly from Weatherford, to Anadarko, to ...

, called Great Plains Country, do all fit west of I-35, including the easternmost counties in the grouping,

Stephens Stephens is a surname. It is a patronymic and is recorded in England from 1086. Notable people with the surname include: *Alexander H. Stephens (1812–1883), Vice President of the Confederate States of America *Alison Stephens (1970–2010), Brit ...

and

Jefferson Jefferson may refer to: Names * Jefferson (surname) * Jefferson (given name) People * Thomas Jefferson (1743–1826), third president of the United States * Jefferson (footballer, born 1970), full name Jefferson Tomaz de Souza, Brazilian foo ...

. But, while most of the 16 counties of

Northwest Oklahoma Northwestern Oklahoma is the geographical region of the state of Oklahoma which includes the Oklahoma Panhandle and a majority of the Cherokee Outlet, stretching to an eastern extent along Interstate 35, and its southern extent along the Canadi ...

, called Red Carpet Country, are also west of I-35, the two easternmost in that grouping, Kay and

Noble A noble is a member of the nobility. Noble may also refer to: Places Antarctica * Noble Glacier, King George Island * Noble Nunatak, Marie Byrd Land * Noble Peak, Wiencke Island * Noble Rocks, Graham Land Australia * Noble Island, Great B ...

, each have some land area east of I-35. Then, the department includes 12 counties in Central Oklahoma, called Frontier Country, around Oklahoma City. Portions of that grouping, like

Canadian County Canadian County is a county located in the U.S. state of Oklahoma. As of the 2020 census, the population was 154,405, making it the fifth most populous county in Oklahoma. Its county seat is El Reno. The county is named for the Canadian Ri ...

, are entirely west of I-35. And, the department has established a South Central grouping of 7 counties, called Chickasaw Country, some of which, like Carter County, have more land west of I-35 than east.

References

{{Coord, 35.5, N, 99.0, W, format=dec, display=title, type:adm1st_scale:3000000_region:US-OK Regions of Oklahoma