How did Tucson get its name?

The Spanish name of the city, Tucsón [tukˈson], is derived from the O'odham Cuk Ṣon [tʃʊk ʂɔːn], meaning "(at the) base of the black [hill]", a reference to a basalt-covered hill now known as Sentinel Peak. Tucson is sometimes referred to as "The Old Pueblo".