Goulies and Ghosties and things that go Aagghh! in the night.
A number of persons won't go hiking in the Canyon with me because they think it is dangerous.
Not in the sense that people who go to the Canyon with me are never seen again (no, that has never really happened), but because they feel that the desert and particularly the Canyon are inherently fraught with peril. After all, the desert is filled with things that bite, scratch, sting, poison, and eat people. On top of that, the Canyon has all those sheer cliffs just waiting for the hapless hiker to fall over.
Statistically speaking, the most dangerous part of your hike will be the drive up to the rim. BUT, there are some things that the hapless hiker needs to be aware of.
About seventy percent of hikers visit the Canyon during the summer. During the summer, temperatures at the River will top 100, or 110. Because the black rocks of the Inner Gorge collect heat all day long and release it at night (the ultimate passive solar heating system) it doesn't even cool down after dark.
One May while on a rim-to-rim, I panted in the sun whilst crossing the open, exposed section of the North Kaibab. As I approached the looming walls of the Inner Gorge I thought: good, shade at last. Well, it was shade, but it wasn't cool. It was like walking into a big radiant heater!
In summer, rangers have to perform five to six emergency evacuations every day. Let's repeat that: five to six a day. No wonder they are so bent out of shape when you tell them you want to hike rim to rim to rim to rim wearing Crocs and carrying a six pack of Coors.
Hiking during summer is not a good idea. However, if this is the only time you have to hike the Canyon, drink lots and lots of water, hike during the cooler part of the day (before 10 AM and after 4 PM, eat salty snacks, and take it easy. Chances are you won't die of heat stroke, but why do you want to suffer in any case? Also keep in mind that the body can only absorb one liter of water per hour. This means you cannot hike down into the Canyon without drinking and then rehydrate during your 15 minute rest stop of Phantom Ranch before you start hiking back out.
Cold? In the desert? Well, the south rim is at 7,000 feet, and it does snow. It even snows (rarely) at Phantom Ranch. Not as many people get into trouble in the cold, but then only ten percent of hikers visit in the winter. Hypothermia, or reduced body heat, is responsible for 85 percent of all outdoor deaths.
If it is raining at Phantom in the winter, it is often snowing on the Rim. Hiking out doesn't keep you warm if you are also wet and there is a wind (which there almost always is in a storm). In winter, do not wear cotton. Silk, wool, fleece, or any of the wicking family of long underwear will do nicely, and don't have to be expensive. A cotton tee shirt, which almost everyone hikes in, gets wet, and you have that wet, clammy, cold layer of clothing right next to your shrinking skin.
Always carry rain gear, no matter what time of year. In winter, it can be cold enough that you will want to wear a ski hat and gloves while walking out. I have hiked out in a blizzard in long johns, a fleece sweatshirt, fleece gloves and hat, and full rain gear.
SLIPPERY TRAILS AND ROCK FALLS
Most hikers go down the corridor trails in sandals, tennies, bare feet, etc. etc. These are good trails, but they are not that good. Invest in a pair of boots and some good, thick socks, and your feet will thank you.
There is not much one can do about rock slides, but getting hit by a rock is really rare. Be very aware of rolling rock noises, particularly after a storm, and never, never, cut switchbacks, for this loosens the rocks up and sets them up to fall at a later time.
More people are afraid of rattlesnakes and mountain lions in the Canyon than they are of rain, but actually more people have died from getting too cold in a storm than have been killed by either animals. I can't actually find a story about anyone who has died of snakebite in the Canyon. Of course, out of 8,000 bites a year in the U.S., only about eight die, and most of them belong to snake handling cults, so it is not surprising that I can't find a statistic for the Canyon. Incidentally forty people a year are killed by domestic dogs, so I guess that makes the family pet four times as dangerous as a rattler.
There are rattlesnakes in the Canyon, and they do bite. However, rattlers are notoriously non-aggressive, and given the choice they will slither away and the hiker will never even see them. If you spied an elephant walking down the road, would you run up and bite it in the leg? You are much bigger to a snake than an elephant is to you. Rattlers use their venom to hunt for food, and even if they strike a human they are likely not to inject venom.
That said, occasionally a person is snake bit and venom is injected. Ninety percent of bites occur when people are playing with or trying to pick up the snake. There is an easy fix to this which should be obvious even to the unobservant mind -- DON'T PICK UP THE SNAKE!
There are poisonous spiders and a poisonous scorpion in the Canyon, but usually a bite will not hurt a large, healthy person. I've had four hikers bit by Bark Scorpions, and they all suffered a bit of discomfort. An allergic reaction to a bee or wasp, can be life-threatening, however. Bees and wasps kill about 100 people a year, and I don't mean Killer Bees.
There are bears in the forest, but they don't bother people. There are mountain lions on both rims, but they usually don't bother people, either. However, if you hike with small children, keep them in sight. It is much more important that you protect them from sunburn and dehydration, but one would hate to lose a child to a lion.
Overall: be prepared. Bring the ten essentials. Don't let your group get too scattered along the trail. You may think you are doing a weaker friend a favor by taking weight from his pack, but don't remove his food, water, and extra clothing and then vanish into the mist. Keep an eye on the weather. Don't mess with Mother Nature -- she can be very unforgiving.
Some Statistics from Over the Edge: Death in Grand Canyon:
39 falls inside Grand Canyon (almost all off-trail)
49 falls from Rim (most climbing over guard rails)
65 environmental:33 heat, 23 cardiac, 6 hypothermia
8 flash floods
29 river runners
17 River crossers
7 fell in from shore
6 vanished from camps into River
128 airline crash 1956
227 other aircraft
8 rock fall
Biggest killer in the Canyon: "Male Ego". Solution: always hike with a male and make him go first.