The Hassayampa River is an intermittent river, the headwaters of which are just south of Prescott, Arizona, and flows mostly south towards Wickenburg, entering the Gila River near Hassayampa. Although the river has only subsurface flow for much of the year, it has significant perennial flows above ground within the Hassayampa River Canyon Wilderness and the Nature Conservancy's Hassayampa River Preserve, near Wickenburg. The river is about 113 miles (182 km) long, with a watershed of 1,410 square miles (3,700 km2), most of it desert.