"Ajo" (pronounced ah-ho) is Spanish for garlic, and some say the town got its name from the wild garlic that grows in the area. Others claim the word is a bastardization of the Indian word au-auho, referring to red paint derived from a local pigment.
For many years Ajo, like Bisbee, was a thriving Phelps Dodge Company town. Copper mining had been attempted in the area in the late 19th century, but it wasn't until the 1911 arrival of the Calumet & Arizona Mining Company that the region began to be developed profitably. Calumet and Phelps Dodge merged in 1935, and the huge pit mine produced millions of tons of copper until it closed in 1985. Nowadays Ajo is pretty sleepy; the town's population of 4,000 has a median age of 51, and most visitors are on their way to or from Rocky Point, Mexico. At the center of town is a sparkling white Spanish-style plaza. The shops and restaurants that line the plaza's covered arcade today are rather modest. Unlike Bisbee, Ajo hasn't yet drawn an artistic crowd—or the upscale boutiques and eateries that tend to follow. Chain stores and fast-food haven't made a beeline here either—you'll find only one Dairy Queen and a Pizza Hut in this remote desert hamlet.