Less than half a mile into a 10-mile hike to a backcountry spot in Yellowstone this summer, my companion looks downriver as we try to figure out how to make our way across. High snowmelt meant that the usual crossing point was far too fast and deep, so we hiked half a mile downstream until the river plain opened up. Even with the shallower, slower water, it was tricky getting across. Fortunately, we had waders (for fishing at our eventual destination), which helped the crossing.