There were several problems.

First, the mountains follow a same pattern over and over: Path to steep fall-away gravel/sand to large boulders. Why they placed the large boulders at the top I have no idea!

Second, we were hiking in running shoes and basketball hi-tops.

Third, the cacti. They were hiding everywhere and here’s something you may not have known about some cacti: they have two kinds of quills (called spines). The first is the obvious, seen in this photo. What you can’t see is that in this sort of cactus, there are tiny invisible quills that will get you if you brush the cactus at all. They disperse 25-50 of these daggers at a time. If you click on this photo to enlarge and look next to the big spines you'll see tufts of the small spines.

Everyone got hit at some point.

Emma got hit more than most.