sentences:  The Dewey–Humboldt area was a census-designated place (CDP) at the 2000 census, at which time its population was 6,295.Dewey–Humboldt was incorporated on December 20, 2004, from the existing unincorporated towns of Dewey and Humboldt, located adjacent to one another in the Agua Fria River Valley, 15 miles east of Prescott.After discovery of gold on Lynx Creek in the spring of 1863, the Dewey area was settled around the summer 1863 by pioneer prospector, rancher and Native American Exterminator King Woolsey (1832–1879), who founded the Agua Fria Ranch, in what was then known as "Woolsey Valley," to supply the miners.