my venture crew just did the narrows in zion, awesome trail! you're waking in a river the whole time (trekking poles almost required) and you walk back up the canyon where it's only about 10' wide in places. it's 14mi total but you need back country permits for the last 6-7mi of it. and we didn't have time to do it all anyway. who's done any hiking in zion nat'l park? if so what trails?