Now I spoke with one of my Native American friends who told me that it is definitely not used anymore due to its also very toxic properties which can seriously injure brain and bodily functions, or cause death. I'm going to get all the warnings about Datura done with now, but the gist of it is; don't eat it or you're taking your life into your own hands. Datura is a part of the nightshade family containing naturally occurring tropane alkaloids. These plants are essentially for landscaping, not culinary, use. If ingested, get to the hospital immediately for treatment; it will take 24 - 36 hours for the plant to get out of the system with, hopefully, no side effects or damage. Consider yourself thoroughly forewarned; now lets get back to Moonflower Canyon itself.
The Canyon is surrounded by sandstone walls and many a cave has developed due to erosion; or perhaps helped to form by ancient hands. I've seen folks camp in or nearby the caves; but like any campsite keep it clean, and most especially do NOT damage the sandstone walls. You were there, but now you're gone; please don't carve your name to carry on.
Moonflower Canyon is one of those places that, yes, you can see ancient Native American history; but it is a place that you can camp for the night, or bring a picnic meal and visit for the day. It is one of those places that is tranquil, bringing rest to the body, mind and soul. Enjoy the soothing.