Moro Rock is a

granite dome Granite domes are domical hills composed of granite with bare rock exposed over most of the surface. Generally, domical features such as these are known as bornhardts. Bornhardts can form in any type of plutonic rock but are typically composed o ...

rock formation in

Sequoia National Park Sequoia National Park is an American national park in the southern Sierra Nevada east of Visalia, California. The park was established on September 25, 1890, and today protects of forested mountainous terrain. Encompassing a vertical relief ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

, United States. It is located in the center of the park, at the head of

Moro Creek Moro may refer to: Events * Moro Crater massacre (1906), an engagement in the Philippine–American War * Moro River Campaign (1943), a World War II campaign between Allied and German forces on the Moro river and its headwaters in Italy * Moro ...

, between

Giant Forest The Giant Forest, famed for its giant sequoia trees, is within the United States' Sequoia National Park. This montane forest, situated at over above mean sea level in the western Sierra Nevada of California, covers an area of . The Giant Forest ...

and Crescent Meadow. A stairway, designed by the

National Park Service The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational propert ...

and built in 1931, is cut into and poured onto the rock, so that visitors can hike to the top. The view from the rock encompasses much of the Park, including the

Great Western Divide The Great Western Divide is a Sierra Nevada mountain range that forms part of the border between the Kings Canyon and Sequoia National Parks. Some of the summits of the Great Western Divide reach well over . The High Sierra Trail crosses the ra ...

. Use of this trail is discouraged during

thunderstorm A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are some ...

s and when it is snowing. The name "Moro Rock" derives from a blue roan

mustang The mustang is a free-roaming horse of the Western United States, descended from horses brought to the Americas by the Spanish. Mustangs are often referred to as wild horses, but because they are descended from once- domesticated animals, the ...

of color the Mexicans call ''moro'', owned by one Mr. Swanson of Three Rivers in the 1860s

Recreation

The road to Moro Rock is closed in winter, so visitors need to hike 2 miles to reach the viewpoint. The road is open in summer so the hike is shortened. The 1996 general plan for the park calls for the road to Moro to be closed, and replaced by a shuttle. As of June 2012, the road is open to general traffic only during weekdays; on weekends, the shuttle is running and the road is closed to general traffic. The west face of Moro Rock offers 1,000 vertical feet of cracks and knobs for rock climbing. However, climbing is prohibited during peregrine falcon nesting season on the South and East faces (up to Full Metal Jacket).

Geology

Moro Rock is a dome-shaped granite

monolith A monolith is a geological feature consisting of a single massive stone or rock, such as some mountains. For instance, Savandurga mountain is a monolith mountain in India. Erosion usually exposes the geological formations, which are often ma ...

. Common in the Sierra Nevada, these domes form by exfoliation, the

spall Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ba ...

ing or casting off in scales, plates, or sheets of rock layers on otherwise unjointed granite. Outward expansion of the granite results in exfoliations. Expansion results from load relief; when the overburden that once capped the granite has eroded away, the source of compression is removed and the granite slowly expands. Fractures that form during exfoliation tend to cut corners. This ultimately results in rounded dome-like forms.

Stairway

The first stairway leading to the summit of Moro Rock was constructed of wood and installed in 1917. This stairway deteriorated significantly by the late 1920s, and was replaced in 1931 by the present Moro Rock Stairway, built by the

Civilian Conservation Corps The Civilian Conservation Corps (CCC) was a voluntary government work relief program that ran from 1933 to 1942 in the United States for unemployed, unmarried men ages 18–25 and eventually expanded to ages 17–28. The CCC was a major part of ...

. Unlike the earlier stairway, the new stairway adopted a design policy of blending with the natural surfaces to the greatest extent possible. The 797-foot-long stairway was designed by

landscape architect Merel S. Sager and engineer John Diehl, following natural ledges and crevices. It has 400 steps that lead to the summit of Moro Rock. Changes since the original construction have impaired the integrity of the design.

References

External links

* * * {{National Register of Historic Places Granite domes Sequoia National Park Landforms of Tulare County, California Rock formations of California