Bill Williams River

River Streamflow Levels

Seasonal Discharge Comparison

Streamflow Elevation Profile

The Bill Williams River is a 46.3-mile-long (74.5 km) river in west-central Arizona where it, along with its tributary, the Santa Maria River, form the boundary between Mohave County to the north and La Paz County to the south. It is a major drainage westwards into the Colorado River of the Lower Colorado River Valley south of Hoover Dam and Lake Mead, and the drainage basin covers portions of northwest, and west-central Arizona. The equivalent drainage system paralleling the east–west lower reaches of the Bill Williams is the Gila River, which flows east-to-west across central Arizona, joining the Colorado River in the southwest at Yuma. The confluence of the Bill Williams River with the Colorado is north of Parker, and south of Lake Havasu City.To the north of the river are the Artillery Mountains, the Rawhide Mountains and the Bill Williams Mountains. To the south lie the Buckskin Mountains. The old mining camp of Swansea (now a ghost town) lies in the Buckskin Mountains about 3.7 miles (6.0 km) south of the river.The two tributaries that form the Bill Williams are the Big Sandy River and the Santa Maria River. Alamo Lake, a flood control reservoir, lies just west of the confluence of the two tributaries. The reservoir and state park is a major fishing and recreation region on the river. The confluence of the Bill Williams River with the Colorado River is just north of Parker Dam and the entire riparian environment has state parks and wilderness areas: Buckskin Mountain State Park, Cattail Cove State Park, and the Gibraltar Mountain, Swansea, and Cactus Plain wilderness areas.