Health & Safety

Health hazards range from mild headaches to grizzly-bear attacks. Because most of us live at or near sea level, the most common health hazard is discomfort caused by altitude sickness as we adjust to the parks' high elevations, a process that can take a day or more. Symptoms include headache, fatigue, nausea, loss of appetite, muscle pain, and lightheadedness. Doctors recommend that, until acclimated, travelers should avoid heavy exertion, consume light meals, and drink lots of liquids, avoiding those with caffeine or alcohol.

Two waterborne hazards are Giardia and Campylobacter, with symptoms that wreak havoc on the human digestive system. If you pick up these pesky bugs, they might accompany you on your trip home. Untreated water from the parks' lakes and streams should be boiled for at least 5 minutes before consumption or pumped through a fine-mesh water filter specifically designed to remove Giardia.

To be on the safe side, you might want to keep a first-aid kit in your car or luggage, and have it handy when hiking. It should include, at the least, butterfly bandages, sterile gauze pads, adhesive tape, an antibiotic ointment, pain relievers for both children and adults, alcohol pads, a pocket knife with scissors, and tweezers.

Bear Encounters

Most people have a healthy respect for bears and are content to view them from a distance. But because a close encounter can happen unexpectedly, you need to know how to handle yourself. First, be aware that what matters most to a bear are food and cubs. If you get between a sow and her cubs, you could be in trouble. If a bear thinks that the food in your backpack is his, you have a problem.

Unless bears have already developed a taste for human food, though, they won't come looking for you. Make a lot of noise on the trail through bear habitat, and Ursus horribilus will give you a wide berth. Don't camp anywhere near the carcass of a dead animal; grizzlies sometimes partially bury carrion and return to it. Hang your food bag high in a tree, keep your cooking area distant from your campsite, and don't keep any food or utensils in your tent -- or even clothes worn while cooking. Soaps and other perfumed items can also be attractants.

Avoid hiking at night or in meadowy mountain areas if visibility is poor. Bears have an extremely good sense of smell but poor eyesight.

If you encounter a bear, here are some things you should and should not do:

Do not run. Anything that flees looks like prey to a bear, and it might attack. Bears can run at more than 30 mph. The bear might bluff charge, but you're best off holding your ground.

Avoid direct eye contact.

If the bear is unaware of you, stay downwind (so that it can't catch your scent) and detour away from it slowly.

If the bear is aware of you but has not acted aggressively, slowly back away.

Do not climb a tree. Although black bears have more suitable claws for climbing, grizzly bears can climb trees, too.

If you're attacked, drop to the ground face down, clasp your hands over the back of your neck, tuck your knees to your chest, and play dead. Keep your backpack on -- it can act as armor. Only as a last resort should you attempt to resist an attack and fight off a bear.

If you carry pepper spray, be sure that it's handy when you're in potential bear habitat, not buried in your backpack. If you use it, aim for the bear's face and eyes. After you use it, leave the area: Bears have been seen returning to sniff about an area where spray has been used.