 It is situated on the Arkansas River at the foothills of the Ozark Mountains in northeast Oklahoma , a region of the state known as " Green Country " . Considered the cultural and arts center of Oklahoma , Tulsa houses two world @-@ renowned art museums , full @-@ time professional opera and ballet companies , and one of the nation 's largest concentrations of art deco architecture . The city has been called one of America 's most livable large cities by Partners for Livable Communities , Forbes , and <unk> America . FDi Magazine in 2009 ranked the city no . 8 in the U.S. for cities of the future . In 2012 , Tulsa was ranked among the top 50 best cities in the United States by BusinessWeek . People from Tulsa are called " Tulsans " . 
