supporting the sky. It formed when volcanic magma pushed upward into the horizontal sedimentary rocks to create the plateau. The liquid rock lifted the rocks above into a huge blister, but failed to reach the surface to create a volcano. As the dome of rock eroded, the solidified magma at its core was revealed. Today the rounded summit of Navajo Mountain consists of the exposed, intruded core, while the flanks of the mountain are draped with upturned layers of Navajo sandstone. These tilted have eroded into towering fins and buttresses, visible from the trail just before the descent into Cliff Canyon.
Exploration of Rainbow Bridge
Navajo Bridge was first publicized by the Cummings–Douglass party in 1909 after a long, difficult journey from Oljeto Trading Post, 50 miles to the east. The group brought back such glowing reports of the sandstone bridge that President Taft used the Antiquities Act to create Rainbow Bridge National Monument the following year. A few tourists reached the remote bridge during the next few decades, but to do so they had to make an arduous pack trip of many days from Oljeto. Later, the trail was built, shortening the journey considerably. In the 1950s Rainbow Bridge became a popular side hike for river runners traversing the depths of Glen Canyon on the Colorado River. It was still a 7-mile hike from the Colorado River, up Forbidding and Rainbow Bridge Canyons. Mass tourism at Rainbow Bridge began with the filling of Lake Powell in the 1960s, which marked the end of the bridge’s isolation. Now Rainbow Bridge is a major destination for private boaters, tour boats, and aircraft.
3 South Bass Trail to Hermit Trail
MAPS Havasupai Point, Shiva Temple, Grand Canyon, Piute Point U.S.G.S.
SEASON Mid September–May.
BEST October–November, March–April.
WATER Serpentine Canyon, Turquoise Canyon, Slate Creek, Boucher Creek, and Hermit Creek.
PERMITS Required for camping within Grand Canyon National Park.
RULES Campfires are not allowed in the national park backcountry. Pets are not allowed on trails or in the backcountry in the national park.
CONTACT Grand Canyon National Park, P.O. Box 129, Grand Canyon, Arizona 86023, (928) 638-7888, www.nps.gov/grca.
HIGHLIGHTS The Tonto Trail winds for over 70 miles along the Tonto Plateau through the eastern Grand Canyon. This hike covers the remote western half of this scenic trail. Starting from the South Bass Trail, the hike passes near the Grand Scenic Divide, where Grand Canyon geology changes dramatically. West of the Grand Scenic Divide, a red sandstone plateau called the Esplanade forms a major terrace about 1700 feet below the canyon rim. The Esplanade abruptly ends at the Grand Scenic Divide, and the Tonto Plateau takes over as the Grand Canyon’s major mid-canyon terrace. This bench is about 3500 feet below the rim and reflects the gray-green color of its underlying shale rocks. Several side canyons allow side trips to the Colorado River and some of its major rapids, as well as exploration upstream.
PROBLEMS None of the trails are maintained and you will encounter trail damage and washouts. Your rate of progress will be slower than you expect. Water sources are far apart, and each hiker should have sufficient containers to carry water for an overnight dry camp.
Warning: Map miles do not accurately reflect hiking distances in the Grand Canyon because of the rough terrain. This hike is dangerous during the summer. Do not attempt it from May through mid-September, when temperatures commonly exceed 100˚F.
HOW TO GET THERE To reach the end trailhead from Grand Canyon Village on the South Rim, drive to the end of the West Rim Drive, and park at the Hermit Trailhead. During the summer season the West Rim Drive is closed to private vehicles. A free shuttle service is provided from Grand Canyon Village, so you will need to leave a vehicle there. The Bright Angel Trailhead at the west end of the village is a logical place to leave your vehicle because there is a shuttle bus stop there. To reach the starting trailhead, drive the Rowe Well Road west from the Bright Angel Trailhead. The road soon becomes graded dirt. Turn right 4.9 miles from the village. Drive 18.1 miles, and then turn right on the Pasture Wash Road. This road is not maintained and may be impassable during and after a wet winter because of deep mud. Continue 7.0 miles to the end of the road at the South Bass Trailhead.
DESCRIPTION The South Bass Trail descends to the east through open pinyon pine and juniper forest and switchbacks down to cross the head of Garnet Canyon. Eroded, short switchbacks take you through the Coconino sandstone.
Eventually the trail comes out onto the Esplanade, a broad terrace formed in the soft, red Hermit shale. The South Bass Trail can’t descend the head of Bass Canyon because of the Esplanade sandstone cliff. Instead, it heads north along the west rim of the canyon for nearly a mile before finding such a fault break and descending. Once below the Esplanade sandstone, the trail rounds a point and doubles back toward the head of the canyon, exploiting breaks in the Supai sandstone layers as it finds them. It descends the Redwall limestone down to the bed of the canyon. Routes through the Redwall limestone are scarce because of the highly resistant nature of the limestone, and its constant thickness of more than 500 feet throughout the Grand Canyon. Only about 200 known routes have been discovered through the hundreds of miles of Redwall cliff exposed in the canyon. William Bass built his trail through one of these breaks, following an old Native American route.
Rock Faults
Most of the trails and routes within the Grand Canyon take advantage of faults to descend through cliff-forming layers of rock such as the Esplanade sandstone. Faults are commonly formed when rock layers are pushed up or down and the rock fractures to allow the movement. The shattered rock erodes into ravines and slopes, creating routes through otherwise vertical cliffs.
Below the Redwall limestone gorge, Bass Canyon gradually opens up as the trail descends into the green and purple Bright Angel shale. Here, the trail stays mostly east of the bed. When the trail meets the brown, coarse Tapeats sandstone, it crosses the Tonto Trail. Turn right (east) on the Tonto Trail.
The South Bass Trail continues to the Colorado River, and is a worthwhile side trip. Of course, you can also go to the Colorado River for water.
Tip: You may find seasonal water at Bass Tanks, where the 7.5 minute topographic map shows a spring, about 0.7 mile north on the South Bass Trail.
Heading east on the Tonto Trail, you’ll quickly find that the Tonto Plateau is not as level as it appears from the South Rim. In fact, it is remarkably rough. The trail dips into shallow ravines and winds around low ridges. The Tonto Trail also frequently climbs or descends to avoid obstacles. As compensation, the route alternates between spectacular points overlooking the Granite Gorge and the Colorado River, and the towering walls of side canyons. The trail eventually rounds the northeast end of the Grand Scenic Divide and heads southwest into Serpentine Canyon, the first of many named and unnamed side canyons. Serpentine Canyon usually has water where the Tonto Trail crosses it, and if not, it’s an easy walk down the bed to the Colorado River. Serpentine Canyon, 8.4 miles from the South Bass Trailhead, makes a good first night’s camping spot for small groups.
Granite Gorge from Tonto Trail
Cliff and Terrace
In the canyon, the horizontal, sedimentary rock layers erode according to their hardness. Hard rocks such as limestone and sandstone form cliffs, while soft rocks such as shale and siltstone form slopes. Since these types of rocks tend to alternate in the cross section, the Grand Canyon has a staircase appearance of alternating cliffs and slopes. Terraces form where the soft layers are especially thick, so that the cliffs above retreat back and expose large, relatively level expanses of the lower cliff-forming layer. In the case of the Esplanade terrace along the upper South Bass Trail eastward, the surface of the terrace is formed on the upper sandstone