By LAURA MAHER

When people speak of my city’s river, they say: declined. What they mean is: dry. Only modern cities can survive on the promise of water. Early people settled just east of the river, on the then-fertile floodplain that offered easy access to water, mud, fish, grasses, all the necessary components to forge a life in the desert. In the summer, I imagine cool breezes.

Tucson lies in a valley between four mountain ranges, so each range becomes a landmark. A trained eye can decipher a way through the desert using these mountains alone, though this eye will also see the lines of cottonwood trees, will find where water runs silently underground—the Santa Cruz River (translation: “Holy Cross”) long buried under a bed of pummeled stone, sand, bits of mica.