"Subway" in Zion National Park is a semi-technical 9.5-mile slot canyon hike that requires wading, swimming, and scrambling over large rocks. A 60-foot line is required to safely descend some drops.
There is no trail and most of the time hikers just walk in the creek. Permits are required and no overnight camping is allowed. Even though "Subway" is a challenging hike, the amazing scenery is worth the trip. We made this trip several years ago.
After descending a steep grade, the trail arrives at a small pool of water. There is considerable loose rock on the trail, so the first people down need to stand under a ledge so that they do not get hit by falling rocks as others descend into the canyon. We made the hike when the water level was low, but we still had to swim in a few places
Swimming was required at one place where the channel was narrow and deep. Directly over the channel was a large boulder that appeared to have been in place for a long time, so we were not concerned that it would fall while we were swimming under it in the water.
This is where "Subway" gets its nickname because the creek channel looks like a subway tunnel.
