Russell Lee, "Water witch walks in the direction that stick heads him. Pie Town, New Mexico," 1940, found via this article
I run a fingernail along that branching witch-hazel, feeling for a thrum at every Y. Yes, the answer comes, pick me, cut here. My penknife slips as it bites in, and I nick myself right at the moment I sever branch from limb. A little blood wet on the blade and the branch—a small give- back to the brushy tree—and I’m almost ready. I’ll be over there, over those hills, walking the dry land, palms up and fingers lightly wrapped around the Y as it calls out down through rock, nods when the water held in the branch is answered by the water down below. No matter how far off or deep, no matter how parched, water will find water, the cut tree sings.