“Whoa up,” I called. One of the pack horses had broken loose and was causing havoc in our seven horse string. It was the first day of a three-week pack trip and all the horses were antsy, particularly my Spanish Mustang, Chocolate. He wasn’t happy being tucked in behind horses he didn’t know, leading one he didn’t like. I hopped off Chocolate and foolishly left him loose, breaking one of the golden rules of backcountry travel: always hang on to your horses.