The longest river in Arizona is the Colorado River, a 1,450-mile river extending from the Rocky Mountains in Colorado to Gulf of California in Mexico. The Colorado River serves as most of the Arizona-California state border. This river passes by such Arizona cities as Yuma, Bullhead City and Lake Havasu City. Many of Arizona's rivers are tributaries of the Colorado Rivers, including the Gila, Lower Colorado, Virgin and Paria rivers.
The Gila River flows through southern Arizona from Sierra County, N.M., to the Colorado River near Yuma. The entire length of the Gila River is 650 miles, making it the second-longest river in the Grand Canyon State. In Arizona, the Gila River is within an hour south of the greater Phoenix area. Some of the Gila River's tributaries are the Santa Cruz, San Pedro, Agua Fria and San Francisco rivers.
At 315 miles, the Little Colorado River is the third-longest river in Arizona and the Colorado River's second-longest tributary. This river flows from the Colorado River in the northern region of the state. This river splits into two forks --- east and west --- in Arizona's White Mountains and joins back together in the Apache National Forest. In eastern Arizona, the Little Colorado River flows in western New Mexico. The western end of the Little Colorado runs through the Grand Canyon and Painted Desert regions.
The Salt River is a 200-mile river in south-central Arizona. This river flows through Arizona's capital city, Phoenix, and is the largest tributary of the Gila River. The source of the Salt River is the confluence of the White and Black rivers in Arizona's White Mountains. The Salt and Gila rivers meet approximately 15 miles west of Phoenix. Some of the Salt River's tributaries are the Verde River, Arizona Canal and Tonto Creek.
Located in southern Arizona, the Santa Cruz River is the state's fifth-longest river at approximately 184 miles. The source of this river is the San Rafael Basin. From this Basin, the Santa Cruz River flows through the Patagonia Mountains into northern Sonoma, Mexico. This river is more than 6,000 feet above sea level at certain points of the Patagonia Mountains. Santa Cruz's river basin supports two endangered species plants, the Madrean ladies' tresses and Huachuca water umbel.