Every time you drive past a canal in the Valley, you could be looking at a route first carved through the desert more than 1,000 years ago. Beginning around A.D. 200, ancestral Sonoran Desert communities built an enormous network of canals off the Salt River using hand tools. The system eventually carried water across thousands of acres and helped support tens of thousands of people in what is now metro Phoenix. Much of the canal system was abandoned around A.D. 1450. Centuries later, settlers including Jack Swilling recognized the old channels, cleared portions of them and began running water through them again. That history also helped inspire the name Phoenix: a new city rising from what had existed before it. Even crazier, archaeological research suggests many of the Valley’s modern canal routes still follow those ancient paths. The descendants of the people who built them remain in Arizona today, including communities within the Gila River Indian Community and Salt River Pima-...