On a recent hike in Zion NP, I came across some rock climbing anchor bolts. There were 5 of them, secured to the top of the rocks at the center of this google map. Maybe these are seen often by others, but it is rare for me to see them.
I don't know why they are in this particular location, so I'll guess. They might provide anchors for rappelling down into Keyhole Canyon on the left. Rappelling from this spot would drop you between the upper narrows and middle narrows sections of Keyhole Canyon. It would also be a big convenience for SAR teams if they had permanent anchors installed where they would likely want them.
I found the map below on this web site. I had walked up the red route line on the right.