The state of Texas is in the south/southwestern region of the United States. In land area, it's the biggest of all the mainland states. In population, it's the second biggest state in the nation (they say everything's big in Texas). Roughly half of the state's population lives in or around Dallas and Houston.
Texas is bordered by Oklahoma on the north, Louisiana and Arkansas on the east, Mexico on the south, and New Mexico to the west. Three rivers, the Rio Grande, the Red River and the Sabine River, provide natural state borders.
Texas has four major physical regions: the Gulf Coastal Plains, the Interior Lowlands, the Great Plains, and The Basin/Range Province.