One of my first guides, on the Bighorn, told me he'd measure a fish for me if I caught one that was big enough. After I caught and released several largish fish, he decided that a nice rainbow I caught was worthy of measurement, at which point he rolled up his sleeve, laid it along his forearm, and proclaimed it a 23" fish. "How do you know?" I asked. "Well," he said, "the last time I was in the tattoo parlor I had them add this line on my arm that's exactly 18" from the end of my middle finger. I used to carry a tape, but kept losing it. Never had that problem again."