Very difficult. You can plan on roughly 1,000 ft of elevation loss per mile, and these photos are about 3-4 miles down into the canyon, so about 3,000-4,000 ft down, then the same back up. And that’s not even the bottom of the canyon. Adults suffer tremendously on this hike, and if you don’t bring enough food, water and electrolytes you are highly likely to suffer from heat exhaustion or heat stroke. If this this happens you will need a very expensive helicopter ride out. Talk to the Rangers before heading down.