Grand Canyon Today

Geography

Geologically, the Grand Canyon extends from Lees Ferry at the foot of the Echo Cliffs 277 river miles downstream to the Grand Wash Cliffs. Although the upper section, Marble Canyon, is not geographically part of the Grand Canyon, the same rock layers are exposed in both canyons. Even though the character of the Grand Canyon changes along its length, many of the same rock layers are present along the entire distance, notably the Kaibab Limestone, the Supai Formation, and the Redwall Limestone.

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Marble Canyon

Marble Canyon

Marble Canyon

The rock layers that form the walls of the Grand Canyon are first exposed at Lees Ferry. Here, Glen Canyon ends abruptly and the Colorado River flows between low banks for a short distance. Once the site of a ferry and a ranch operated by John D. Lee, Lees Ferry is the only point along the river above the Grand Canyon that is accessible by road. Just below the boat ramp, the river starts to cut into Marble Plateau, forming Marble Canyon. Where the river flows under Navajo Bridge (the replacement for the ferry), Marble Canyon is already 800 feet wide and 400 feet deep. Marble Canyon differs from Grand Canyon in that it is a single main canyon with tributary canyons, and the rims are close above the river. As the Colorado River flows southwest, the plateau rises. When Marble Canyon ends at Boundary Ridge, it is 4,000 feet deep and two miles wide.

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Grand Canyon

One of many Grand Canyon summits, distant Vishnu Temple rises higher than the South Rim

One of many Grand Canyon summits, distant Vishnu Temple rises higher than the South Rim

As the Colorado River enters Grand Canyon, the river canyon widens to more than eight miles. Instead of a single, narrow canyon, the Grand Canyon is a complex maze of side canyons, mesas, and buttes. The heads of the major side canyons cut into the rims, forming cliff-bound amphitheaters. The ridges between the side canyons are carved into large mesas, isolated buttes, and towering pinnacles. From the rim viewpoints or from the air, it is obvious that the Grand Canyon is a single canyon system. Down in the canyon, however, along the river or hiking, the rims are partially or completely hidden so it appears as if you're deep in the heart of a mountain range.

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Desert Facade

The Desert Facade rises steeply from the Colorado River's banks at the upper left of this photo

The Desert Facade rises steeply from the Colorado River's banks at the upper left of this photo

As the river continues south through the eastern Grand Canyon, it flows through a canyon floored by the soft rocks of the Bright Angel Shale, and the river banks are relatively accessible. The 550-foot Redwall Limestone cliffs tower above the river. Major side canyons enter mainly from the west, as the river flows close to the east rim. Known as the Desert Facade, the especially steep ramparts below the east rim are a result of a missing rock layer, the Hermit Shale, which causes the near-vertical Coconino Sandstone cliff to rest directly on the cliff-forming Esplanade Sandstone.

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Palisades of the Desert

As seen from Desert View, the steep buttresses of the Palisades of the Desert are caused by a relative absence of the soft layers of shale that form terraces between the Kaibab Limestone, the Coconino Sandstone, and the Supai Group further west in the canyon.

As seen from Desert View, the steep buttresses of the Palisades of the Desert are caused by a relative absence of the soft layers of shale that form terraces between the Kaibab Limestone, the Coconino Sandstone, and the Supai Group further west in the canyon.

As the Colorado River reaches the confluence with the Little Colorado River, the Tapeats Sandstone emerges at river level and forms an inner gorge about 200 feet deep, making the river nearly inaccessible. Towering, cliff-bound summits such as Chuar Butte on the west face the equally imposing Palisades of the Desert across the river on the east.

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Grand Canyon Supergroup

Grand Canyon Supergroup forms relatively open terrain below Desert View

Grand Canyon Supergroup forms relatively open terrain below Desert View

Below Desert View, the river changes course from south to west, and the colorful, tilted layers of the Grand Canyon Supergroup form the floor of the canyon. Desert View, Lipan Point, and Cape Royal are good vantage points for observing the relatively open terrain eroded from the soft shale members of the supergroup. The Colorado River is also readily visible. From a distance, the terrain near the river looks gentle, but only in contrast with the towering cliffs above. It is still very difficult, rough terrain for the hiker.

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Granite Gorge

Middle Granite Gorge

Middle Granite Gorge

Below Moran Point, the Colorado River enters Granite Gorge, as the Grand Canyon Supergroup disappears and the Vishnu Schist is exposed. The V-shaped gorge rises rapidly to 1,500 feet deep, rimmed by the brown Tapeats Sandstone. Access to the river from above is nearly impossible, except down the few side canyons that are not blocked by dry falls or other obstacles. Landing places for river rafts are scarce and the rapids are especially fierce. In fact, five of the hardest ten rapids in the Grand Canyon are found along Granite Gorge.

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Tonto Platform

Soft Bright Angel Shale erodes into broad terrace of the Tonto Platform

Soft Bright Angel Shale erodes into broad terrace of the Tonto Platform

As the Colorado River flows under the two suspension bridges at the mouth of Bright Angel Creek, the site of Phantom Ranch and the crossing point of the trans-canyon Kaibab Trail, Granite Gorge is at its awesome best. The rim viewpoints from Yaki Point to Hermits Rest offer only occasional glimpses of the river, mostly hidden in its steep-sided inner gorge. In this portion of the Grand Canyon, the soft Bright Angel Shale erodes into a broad terrace, the Tonto Platform, about 4,000 feet below the rim.

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Side Canyons

Major side canyons branch north and south from Granite Gorge. Because the river cut through the surrounding plateau south of its highest point, the plateaus beyond the both rims drain to the south. This means that precipitation falling on the South Rim flows away from the canyon, while precipitation falling on the North Rim flows into the canyon. The extra flow makes the north-side canyons longer, so that in the section of the canyon between Moran Point and Hermits Rest the river is much closer to the South Rim than the north. The terrain on the north side of the river is more complex than it is on the south side and most of the major buttes and summits are on the north side of the river. From the South Rim viewpoints, the North Rim is partially obscured by the mesas and buttes rising nearly as high as the rim. From the North Rim, the relief north of the river is more apparent and the South Rim appears to be a monolithic wall.

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The Esplanade

The Esplanade

The Esplanade

About 20 miles west of Grand Canyon Village, the Bright Angel Shale thins to the point that the Tonto Platform tapers away. Meanwhile, the Hermit Shale has become much thicker, so a new terrace, the Esplanade, forms on the top of the Supai Group about 2,000 feet below the rim. The Esplanade becomes broader to the west as the Hermit Shale thickens and is the dominant terrace in the central and western Grand Canyon. Like the Tonto Platform, the Esplanade is also drained by major side canyons and their tributaries.

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Temple Butte Limestone

A new formation appears in the western Grand Canyon- the Temple Butte Limestone. Found only in a few places in the eastern Grand Canyon, the Temple Butte Limestone thickens and becomes a major cliff-forming layer in the western canyon. The Temple Butte Limestone forms the lower cliffs below Toroweap Overlook and helps make the 3,000-foot inner gorge at Toroweap so dramatic.

At Grand Canyon West, the Temple Butte Limestone is much thicker than the overlying Redwall Limestone, and together the two formations form a steep series of cliffs nearly 3,000 feet high. In this area, the Redwall Limestone generally forms the South Rim because the Supai Group and the rocks above have been eroded away. Across the river from Grand Canyon West, the higher North Rim is still formed from the Kaibab Limestone, and the Esplanade is present, carved from the Hermit Shale. The Shivwits Plateau forms the westernmost part of the North Rim, and this extremely isolated area is often capped by lava flows.

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Grand Wash Cliffs

The Grand Canyon ends abruptly about ten miles west of Grand Canyon West, at the Grand Wash Cliffs. This west-facing, 4,000-foot line of cliffs also marks the western edge of the Colorado Plateau. The effect is dramatic- the Colorado River suddenly emerges from the Grand Canyon into gently rolling desert hills. When it is full, Lake Mead, the reservoir created by Hoover Dam, floods the lower Grand Canyon below Separation Canyon. As the Colorado River gradually merges with the still waters of the lake, the river drops its load of sediment, silting in the rapids and creating high silt banks along the river and the lower side canyons. When Lake Mead is low, the river current resumes, but lacks the power to excavate the rapids. The result is that there are no rapids on the Colorado River in the area of Grand Canyon West.

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