Oklahoma is the largest city and is situated in the state of Oklahoma in the US. The city of Oklahoma is 1,606.67 squared kilometers in size. Oklahoma is the most populated city in the great plains region with the exception of Texas. The population of Oklahoma was estimated at 1,358,452 during the last census in the year 2015. Oklahoma city is known for having one of the largest livestock market and several petroleum and gas industries in the region. The city of Oklahoma is around the I-35 corridor which is one of the main transport routes in the US.