http://www.jimmys-adventures.net/hiking-zion-subway/
In Zion National Park, is it possible to hike from Left Fork Trail to Wildcat via the Subway?
It is POSSIBLE, to Wildcat Trailhead (not Wildcat Canyon), though somewhat difficult. It has 3 short climbing problems to overcome, and quite a few swims. The climbing problems are a lot easier with a team of at least 3 people, so Keyhole Falls can be “craned”. See the trip report below, where we did a yo-yo – down from the top, then back out the top.
Tom
The Subway in Zion National Park Video Hike