Oklahoma is a state located in the south-central region of the United States. It is the 20th most populous state in the country and has a diverse economy that includes agriculture, energy, and aerospace industries. The state is known for its Native American history and culture, with over 39 federally recognized tribes residing in Oklahoma. The state's capital is Oklahoma City, which is also the largest city in the state. Other notable cities include Tulsa, Norman, and Lawton. Oklahoma is home to several universities, including the University of Oklahoma and Oklahoma State University. The state is also known for its natural beauty, with attractions such as the Wichita Mountains Wildlife Refuge and the Tallgrass Prairie Preserve.