http://www.okc.gov/ Oklahoma City is the capital and the largest city in the U.S. state of Oklahoma. The county seat of Oklahoma County, the city ranks 31st among United States cities in population. The city's population, from the 2010 census, was 579,999, with a metro-area population of 1,252,987 . In 2010, the Oklahoma City-Shawnee Combined Statistical Area had a population of 1,322,249 residents. Oklahoma City's city limits extend into Canadian, Cleveland, and Pottawatomie counties, though much of those areas outside of the core Oklahoma County area are suburban or rural (watershed). The city ranks as the eighth-largest city in the United States by land area (including consolidated city-counties; it is the largest city in the United States by land area whose government is not consolidated with that of a county). Oklahoma City features one of the largest livestock markets in the world. Oil, natural gas, petroleum products and related industries are the largest sector of the local economy. The city is situated in the middle of an active oil field and oil derricks dot the capitol grounds. The federal government employs large numbers of workers at Tinker Air Force Base and the United States Department of Transportation's Mike Monroney Aeronautical Center. (These two sites house several offices of the Federal Aviation Administration and the Transportation Department's Enterprise Service Center, respectively.) The city was founded during the Land Run of 1889, and grew to a population of over 10,000 within hours of its founding. The city was the scene of the April 19, 1995 bombing attack of the Alfred P. Murrah Federal Building, in which 168 people died. It was the worst terror attack in the history of the United States before the attacks of September 11, 2001, and remains the worst act of domestic terrorism in U.S. history. Oklahoma City lies along one of the primary travel corridors into Texas and Mexico, and is about three hours by car to the Dallas-Fort Worth metropolitan area. Located in the Frontier Country region of the state, the city's northeast section lies in an ecological region known as the Cross Timbers. Since the time weather records have been kept, Oklahoma City has been struck by nine strong tornadoes, eight (E)-F4's and one F5. On May 3, 1999 parts of southern Oklahoma City and nearby communities suffered one of the most powerful tornadoes on record.