The slot canyons that separate fins are very popular geologic features that people love to experience. However, they can also be very dangerous places during rainstorms because of flash flooding. Rain falling in the upper portion of a watershed quickly accumulates as it moves downhill. Slot canyons are choke points that all this water must pass through. The floods can travel with such speed and force that boulders the size of cars are dislodged and blasted down these narrow canyons. Anything caught between the walls and the debris washing through will be pulverized. Because Bryce's slot canyons occur very high in the watershed, flash floods are not as severe as in other places. Nevertheless, for the preservation of your own health, avoid the Navajo Loop Trail during a rainstorm. It is also important while preparing for a backcountry overnight trip that you consult a weather forecast while obtaining your backcountry permit.