The Willamette River Basin (WRB) encompasses 11,600 mi2 (30,000 km2), about 12% of Oregon’s land area. It provides a home for over 70% of the state’s population, primarily in the cities of Portland, Salem, Corvallis, and Eugene. The Willamette River, the 13th largest river in the U.S., drains the Coast Range to the west, the Willamette Valley, and the Cascade Range to the east. The U.S. Army Corps of Engineers operates The Willamette Project, a system of 13 reservoirs with a collective storage capacity of 1.7 million acre feet. These reservoirs support flood control, irrigation, municipal flows, environmental flows, navigation, and recreation. Hydroelectric power plants associated with 8 dams generate electricity used in the WRB and in the wider region. The valley’s 1.56 million acres of crop-lands support high-value products such as grass seed, vegetables, fruits, nuts, and grapes. The river and its tributaries support native coldwater fish species protected by the Endangered Species Act. Like many places in the West, the WRB faces many natural resources challenges such as declining snowpacks, stressed forests, competing water demands, warming rivers, and endangered fish.