claim: Salt River Valley is a river valley that contains the Phoenix metropolitan area.
evidence: The Salt River Valley is an extensive valley on the Salt River in central Arizona , which contains the Phoenix Metropolitan Area .. Salt River. Salt River ( Arizona ). Arizona. Arizona. Phoenix Metropolitan Area. Phoenix Metropolitan Area. Although this geographic term still identifies the area , the name `` Valley of the Sun '' popularly replaced the usage starting in the early 1930s for purposes of boosterism .. boosterism. boosterism. A common dust for testing air filter efficiency was derived from top soil dust from the Salt River Valley , referred to as Arizona Dust .. Salt River. Salt River ( Arizona ). Arizona. Arizona. The dust was found to include small abrasive particles .