Venomous creatures: Several species of poisonous reptiles, scorpions, and spiders exist in the Grand Canyon. While there have been numerous bites, there have been no recorded deaths from any envenomation. Generally, desert creatures are not aggressive toward humans and try to aviod contact with people.

The bites and stings that do happen often occur from intentional handling or the animal accidentally getting trapped between clothing, sleeping bags, footwear, and human skin. General rules for preventing bites and stings include: Do not intentionally handle a venomous animal. Always watch where you place your hands and feet. Avoid placing them blindly under rock ledges, logs, or vegetation as this is where these creatures are commonly found. Shake out clothing and footwear before putting it on. Leave your sleeping bag rolled up until you are ready to lie down and shake it out before getting inside. Use a flashlight while walking at night.

Scorpions: Scorpions are nocturnal and are very active during the summer months. Stings are not uncommon and are painful. While symptoms may very in severity, scorpion bites usually do not require evacuation. The bite will usually spontaneously improve within twenty-four to forty-eight hours.

Rattlesnakes: Rattlesnake bites are uncommon in the Grand Canyon and those that happen are usually the result of directly handling the snake by overly excited and uninformed visitors. Fortunately, like scorpion stings, no one has ever died from a rattlesnake bite in the Grand Canyon. The number one rule is to NEVER try to intentionally pick up a rattlesnake!

While walking at night, use a flashlight. If a snake is causing problems in camp, let your guides know right away and let them handle the situation according to their training. Rattlesnake bites do warrant emergency evacuation for possible antivenin therapy.

Flashfloods: Flashfloods are sudden, powerful floods of water, mud, and desert debris that can race down side canyons during periods of wet weather and high precipitation in the watersheds of side canyon drainages.

Again, while your guides will typically direct your hikes, remember to avoid hiking or wandering up narrow "slot" canyons during monsoon thunderstorm weather (July through September) Also, it’s a good idea to avoid camping in the drainages of even small side canyons just to be safe.

Alcohol: Impairment from alcohol (or drugs) has resulted in countless accidents with injuries, as well as numerous drownings from shore within the Grand Canyon. If you choose to drink, do so responsibly. Use extreme caution at the river's edge and on steep banks. Do not go hiking or climbing. For family members, friends, and companions, discourage excessive comsumption of alcohol and never, never let any intoxicated person out of sight, especially near the river.