The historic natural discharge of the river is around 1,900 cubic feet per second (54 m 3/s), and is now only 247 cubic feet per second (7.0 m 3/s).

However, European Americans did not permanently settle the Gila River watershed until the mid-19th century.ĭuring the 20th century, human development of the Gila River watershed prompted the construction of large diversion and flood control structures on the river and its tributaries, and consequently the Gila now contributes only a small fraction of its historic flow to the Colorado. Indigenous peoples have lived along the river for at least 2,000 years, establishing complex agricultural societies before European exploration of the region began in the 16th century. The river drains an arid watershed of nearly 60,000 square miles (160,000 km 2) that lies mainly within the U.S., but also extends into northern Sonora, Mexico. The Gila River ( / ˈ h iː l ə/ O'odham : Keli Akimel or simply Akimel, Quechan: Haa Siʼil, Maricopa language: Xiil ) is a 649-mile-long (1,044 km) tributary of the Colorado River flowing through New Mexico and Arizona in the United States.

San Francisco River, Salt River, Agua Fria River, Hassayampa River San Simon River, San Pedro River, Santa Cruz River