Like many border towns from Texas to California, the twin cities of Nogales exist in a symbiotic relationship-tied together by family and social connections and a shared economy. Nogales' Port of Entry is bustling with traffic between the United States and Mexico, but the twins are not identical. The 25,000 inhabitants of Nogales, Arizona, enjoy the conveniences of an American town's infrastructure. There are no reliable population figures for Nogales, Sonora, because of the high rate of growth, but every estimate I heard was in excess of 250,000 people-10 times the population of the Arizona twin. Unlike the northern counterpart, the infrastructure south of the border is extremely poor.
Roads are in terrible condition, and most homes lack basic conveniences such as indoor plumbing.
As the population swells, new settlements called colonias that lack electricity are growing on the outskirts of town. Erosion is present everywhere as the vegetation-poor desert hillsides threaten to wash away at the first substantial rainfall and claim the settlement housing. The economy of Nogales, Sonora, once dependent on tourism, now rests solidly on manufacturing. The 1994 implementation of the North American Free Trade Agreement has caused the number of foreign-owned factories, called maquiladoras, to explode. By the estimate of an official with the Nogales Chamber of Commerce, there are now 105 maquiladoras in and around Nogales.