th in the US  - Total 3,751,351 (2010 Census Estimate) -  Density 54.6/sq mi  (21.1/km 2 ) Ranked 36 th in the US Elevation    - Highest point Black Mesa [ 1 ] 4,973 ft  (1,515 m)  - Mean 1,296 ft  (395 m)  - Lowest point Little River [ 1 ] 289 ft  (88 m) Before statehood Oklahoma Territory Admission