Inner canyon trails range from rigorous multiday backpacking adventures to short explorations from river camps. Backpackers often make the Colorado River their goal, but “halfway hikes” can also be very rewarding, offering beautiful river panoramas from viewpoints on the Tonto Trail  or along the Esplanade.
Inner canyon trails lend a sense of intimacy to your explorations, revealing details that are hidden from perspectives on the rim: historic mining camps, springs and seeps, clear-flowing creeks, waterfalls, sandy beaches, and beautifully eroded schist and granite. Many sites are readily accessible only from the river, and chances are you’ll get a wider range of sightseeing in a two-week river trip than you could in years of hiking from the rim.
At river elevations of 1,200-3,200 feet, the inner canyon’s Sonoran Desert climate is like being in Tucson or Phoenix. Expect a 20-30°F difference between rims and river, choosing gear—and food—accordingly. Sun protection is crucial: appropriate clothing, a hat, sunglasses, and sunblock. Many trails have exposed sections, and at midday even the river is in full sun. A light, long-sleeved shirt can help shield you from the intense desert rays.
For summer hikes, thin cotton is best. The rest of the year, polyester fleece and quick-drying fabrics work well for hiking. Be prepared for afternoon showers during Arizona’s monsoon season, mid-July-mid-September.
Bring boots that are broken in, plenty of socks, and an emergency kit. Pack adequate water (including iodine tablets for emergencies and a filtering system for backpacking trips) and salty snacks. If you are hiking near the rims during winter months, you may need crampons, for sale or rent at the General Store.
A good trail map is a must for wilderness backpackers, along with an understanding of desert hiking and route-finding. For example, “Creek” on a map might refer to a dry wash, a year-round stream, or a stream that flows seasonally during spring melt or briefly after a rainstorm.
Before attempting a multiday backpacking trip, research potential water sources. Hiking guidebooks are good resources, as is the online bulletin board managed by the Grand Canyon Hikers and Backpackers Association (www.gchba.org ).
No permit is necessary to day hike in Grand Canyon National Park, but in order to camp anywhere other than the developed rim campgrounds, a backcountry permit is required. The Park Service strongly discourages anyone from attempting to hike from rim to river and back in a day. Unless you are an exceptionally strong hiker, you’ll need to spend at least one night in the canyon, and that means preparing months ahead by applying for a backcountry permit.
When hiking in the backcountry, it’s safest to travel with companions. Also remember that the Navajo, Hualapai, and Havasupai tribes hold land surrounding the park. Be sure to apply for permits if you will be hiking into or across Indian land.