At the end of Riverside Walk, the bottom-up Narrows continues in the Virgin River. That means walking over uneven, slippery rocks; it is a different outing from the paved trail. Flash flooding and hypothermia are real hazards, and river conditions change daily, so check current river and weather conditions before entering. A bottom-up hike from the Temple needs no permit. The 16-mile top-down through-hike from Chamberlain's Ranch does require a wilderness permit and separate transport to its upper trailhead.