We hiked about 1.5 miles of the the South Rim Trail. There are countless opportunities to step right up to the edge and enjoy the view. Surprisingly, park authorities say very few people ever fall over the edge. However, we saw a "Missing Person" notice posted for a 24 year old, White Plains, NY resident whose car was found in the parking lot on April 6th. We were doubly careful after reading this.
We also hiked a half mile down into the canyon. If you enlarge this photo you can see three trail segments, all of them narrow with steep drop offs to one side.
There was also mud, snow and mule poop on the trail just to keep it interesting. We were also a bit light headed, this being our first day at 7000 feet.
We discussed a 2 day mule trip into the canyon at length. Several factors contributed to our decision to not do so. Did you know the mules prefer to walk closest to the canyon side of the trail? While accidents are rare, mules are temperamental animals, possibly spooked by other animals or loud noises (i.e. snakes, coyotes, careless hikers, etc.). The cost is about $800. I am 5 lbs. over the weight limit, so this provided a convenient excuse too.