So, of course, they show up in poetry. “I do not know much about gods,” wrote T. S. Eliot, who grew up along the Mississippi in Saint Louis, “but I think that the river is a strong brown god.” “Under various names,” wrote Czeslaw Milosz, who grew up in Lithuania along the Neman, “I have praised only you, rivers. You are milk and honey and love and death and dance.” I take this to be the first stirrings, even as our civilization did its damming and polluting, of the recognition of what we have lost and need to recover. When human populations were small enough, the cleansing flow of rivers and their fierce floods could create the illusion that our acts did not have consequences, that they vanished downstream. Now that is no longer true, and we are being compelled to reconsider the work of our hands. And, of course, we are too dependent on our own geographical origins to have lost our connection with them entirely.