Official trail signs to the left. None say Keystone Cave trail. That trail starts at the thin, long branch to the right. A note on respect for microbiotic crust, that delicate layer of soil and organisms critical to growth and stabilization of extreme environments. The need for such respect creates a tension with hiking off-trail on unregistered trails. Sedona, I judge, receives sufficient rain and experiences sufficiently moderated temperatures at times, that hiking established unofficial trails, on balance, creates minimal harm. But that tension remains, and should be a factor in choices of hiking adventures.