Mostly it was the advent of geology as a science with broad cultural appeal. The geologic mystery of the canyon is how the south-trending Colorado River made a sudden turn westward to carve its way, cross-grained, through four plateaus.

One of the most influential people in making Grand Canyon a national park was President Benjamin Harrison. He introduced the first bill to Congress to make Grand Canyon a national park, in 1882, as well as two subsequent bills.

The Grand Canyon is a mile-deep gorge in northern Arizona. Scientists estimate the canyon may have formed 5 to 6 million years ago when the Colorado River began to cut a channel through layers of rock. Humans have inhabited the area in and around the canyon since the last Ice Age.

Distance-wise, it’s about 9.5 miles (15.5 km) each way but with an elevation change of over 4,300 ft (1300+ m) and it’s really that elevation change that makes it a tough hike. The hike down generally takes 3-5 hours while the hike up, after a good overnight rest, will typically take 5-9 hours.

How Not to Die at Grand Canyon is a waterproof pocket guide that educates Grand Canyon visitors about the 12 most common hazards that visitors experience, how to avoid them, and how to perform first aid on the spot.

PRICING – The cost of the ride is $155.77 per person, including tax, and is subject to change without notice. A souvenir water bottle is included. RESERVATIONS — Mule rides may be reserved by calling 1-303-297-2757 or toll-free within the United States at 1-888-297-2757.

Staying Overnight Phantom Ranch, at the bottom of the Grand Canyon, is a popular destination for both hikers and mule riders. Overnight hiker dormitories and cabins can be reserved and meals are available for purchase. Advance reservations for meals and lodging at Phantom Ranch are required.

Gopher snakes are the longest snakes in Arizona, and are often mistaken for rattlesnakes. At Grand Canyon, gopher snakes live in both the wooded forests of the Rims and the dry desert scrub inside the Canyon.

Restrictions: 7 or 10 year age limit, depending on trip. 200 lb/94 kg or 220 lb/102 kg weight limit, depending on trip. Visit them at canyonrides.com.

Bring Your Own Horse Share the Grand Canyon experience with your own horse or mule on a dozen designated trails at both the North Rim and South Rim in Grand Canyon National Park. Rides include the famous Bright Angel and Kaibab trails as well as the Arizona Trail, Saddle Horse Loop Trail and more.

Hinnies are more donkey-like in temperament, in part because they are raised by donkeys. However, hinnies are generally quieter, less curious, more compliant and less independent and adventurous than mules. They prefer to avoid trouble rather than confront it.