We were there two weeks ago and the shuttle wasn't open
I believe the shuttles have reopened but with limited seating, and if that's true you don't need a ticket. But I would check on Zion's website for all updated information or talk to the park rangers at the visitor center.
When we were there a couple of weeks ago, the shuttles were not running and most people were having to walk at least a couple of miles down the road to get to the hiking area for the narrows.
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