A river that rises in the Rocky Mountains of northern Colorado and flows southwest for 1,468 miles (2,333 km) to the Gulf of California. It passes through the Grand Canyon. A river that flows east for 900 miles (1,450 km) across Texas, from the Llano Estacado to the Gulf of Mexico. Austin is situated on it. A state in the central US; population 4,939,456 (est. 2008); capital, Denver; statehood, Aug. 1, 1876 (38). Part of Colorado was acquired by the US with the Louisiana Purchase in 1803 and the rest was ceded by Mexico in 1848.