Geographical facts about Texas include that the state's lowest elevation point is at the Gulf of Mexico at sea level, its highest elevation point is at Guadalupe Peak in Culbertson at 8,749 feet above sea level, and the geographical center of the state is located in McCulloch County 15 miles northeast of the town of Brady. Texas is 268,581 square miles in size.
Texas has four major physical regions, including the Gulf Coastal Plains, Great Plains, Interior Lowlands, and Basin and Range Province. The Gulf Coastal Plains include the area from the Gulf of Mexico to the Eastern Cross Timbers and include the cities of Del Rio and San Antonio. This area receives 20 to 58 inches of rain per year. The Great Plains includes the area from Caprock Escarpment in the panhandle to the Balcones Fault to the southeast, and receives 15 to 30 inches of rain per year. The Basin and Range Province includes the area between the Davis Mountains and the Rio Grande River and includes seven peaks over 8,000 feet in elevation.
Texas has 4,790 square miles of water. Major rivers include the Rio Grande, Pecos, Colorado, Red and Brazos. The Rio Grande is 1,896 miles long, making it the longest river in the state.
Texas has over 3,700 named streams. Caddo Lake is the largest natural freshwater lake in Texas, with an area of over 27,000 acres. Other major lakes include Alvarado Park Lake, Lake Austin, Lake Bastrop, Balmorhea Lake and Belton Lake.