I pride myself on having excellent map and navigation skills, but I made a big error on a solo hike across Utah’s San Rafael Swell, a jumble of sandstone and limestone folded into hundreds of valleys and canyons. The Swell is impossible to capture entirely on a map, because serious mischief hides between the contour lines. While traversing, I accidentally ended up a mile away from, and hundreds of feet above, my intended location. I should have backtracked the two or three miles to where I went astray. But it was November, daylight was dwindling, and a winter storm was descending. Instead of retracing my steps, I tried a more direct route to a preplotted location on my GPS and encountered a cliff that I didn’t see on the topo. I almost made a much bigger mistake while scrambling around it—solo, and off my intended route. I avoided serious injury, but spent a cold night in a snowstorm.