Northeastern Oklahoma

Green Country, sometimes referred to as Northeast Oklahoma, is the northeastern portion of the U.S. state of Oklahoma, which lies west of the northern half of Arkansas, the southwestern corner of Missouri, and south of Kansas. The region is noted for its mild rainy climate and beautiful scenery.

Its name was devised in the 1960s by the Oklahoma Department of Tourism and Recreation as one of six travel destination regions within the state, but is the most historically significant of all of them, as the name's usage can be traced to the early part of the 20th century. Another alternate usage of the term can include solely the immediate vicinity of Green Country's principal city, Tulsa; the Tulsa Metropolitan Area or the city of Tulsa proper is often referred to as "Green Country" in its own right. In this case, the terms "Tulsa Metropolitan Area" and "Green Country" are used interchangeably. The region derives its name from the heavily wooded area with many rolling hills and mountains and much foliage, as opposed to western and parts of central Oklahoma, which have geography similar to the rest of the Great Plains region of the United States. Average precipitation totals in Green Country are generally above 40 inches per year, thus making it considerably wetter and greener than most of the state. The area is also one of the most populous regions of Oklahoma, and is home to some of its largest cities.

Northeastern Oklahoma has the most diversified agricultural economy in the state, as well as the state's second largest city, Tulsa. In addition to the area's abundance of foliage and rolling hills, it has more lakes than any other geographical area of Oklahoma, as well as more than half of the state's registered state parks. Oklahoma is one of only four states with more than 10 ecoregions, but six of its 11 ecoregions are located in northeastern Oklahoma.

The heavily-wooded Ozark Mountains and their foothills dominate most of northeast Oklahoma from the immediate Tulsa vicinity south and eastward towards the Arkansas state line, containing both evergreen pine and deciduous forests. In its western counties, the far eastern extent of the Great Plains transition to woodlands through the Cross Timbers region.

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