Cathedral Peak is part of the Cathedral Range

Cathedral Range

The Cathedral Range is a mountain range immediately to the South of Tuolumne Meadows in Yosemite National Park, USA. It is a beautiful range, sculpted by glaciers out of granite. The tops of the peaks in the range were above the level of the highest glaciation, and are therefore uneroded and...

, a mountain range in the south-central portion of Yosemite National Park

Yosemite National Park

Yosemite National Park is a United States National Park spanning eastern portions of Tuolumne, Mariposa and Madera counties in east central California, United States. The park covers an area of and reaches across the western slopes of the Sierra Nevada mountain chain...

 in eastern Mariposa

Mariposa County, California

Mariposa County is a county in the U.S. state of California, located in the western foothills of the Sierra Nevada mountains. It lies north of Fresno, east of Merced, and southeast of Stockton. As of the 2010 census, the population was 18,251 up from 17,130 at the 2000 census...

 and Tuolumne

Tuolumne County, California

Tuolumne County is a county in the Sierra Nevada of the U.S. state of California. The northern half of Yosemite National Park is located in the eastern part of the county. As of the 2010 census, the population was 55,365, up from 54,501 at the 2000 census...

 Counties. The range is an offshoot of the Sierra Nevada. The peak which lends its name to the range derives its from its cathedral

Cathedral

A cathedral is a Christian church that contains the seat of a bishop...

-shaped peak, which was formed by glacial

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 activity: the peak remained uneroded above the glaciers in the Pleistocene

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

.

Geography

The west peak of Cathedral Peak (shown foreshortened in the photograph) is unofficially known as Eichorn Pinnacle, for Jules Eichorn

Jules Eichorn

Jules Eichorn was a California mountaineer, environmentalist and music teacher.- Early years :Jules Marquard Eichorn was born in San Francisco on February 7, 1912 to Hilmar and Frieda Eichorn, who were immigrants from Germany...

, who first ascended a class 5.4

Yosemite Decimal System

The Yosemite Decimal System is a three-part system used for rating the difficulty of walks, hikes, and climbs. It is primarily used by mountaineers in the United States and Canada. The Class 5 portion of the Class scale is primarily a rock climbing classification system. Originally the system was...

 route to its summit on July 24, 1931 with Glen Dawson

Glen Dawson

Glen Dawson is a California rock climber, mountaineer, antiquarian bookseller, publisher and environmentalist.- Early life :...

.

In 1869, John Muir

John Muir

John Muir was a Scottish-born American naturalist, author, and early advocate of preservation of wilderness in the United States. His letters, essays, and books telling of his adventures in nature, especially in the Sierra Nevada mountains of California, have been read by millions...

 wrote in My first summer in the Sierra:

Geology

Cathedral Peak is an intrusion

Intrusion

An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly...

 into an area of older intrusive (or plutonic) and metamorphic rock in the Sierra Nevada batholith. It is part of a grouping of intrusions called the Tuolumne Intrusive Suite. Cathedral Peak is the youngest of the rock formations in the Suite, dating to 83 million years ago. Its composition is mainly Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

-era granodiorite

Granodiorite

Granodiorite is an intrusive igneous rock similar to granite, but containing more plagioclase than orthoclase-type feldspar. Officially, it is defined as a phaneritic igneous rock with greater than 20% quartz by volume where at least 65% of the feldspar is plagioclase. It usually contains abundant...

 with phenocryst

Phenocryst

thumb|right|300px|[[Granite]]s often have large [[feldspar|feldspatic]] phenocrysts. This granite, from the [[Switzerland|Swiss]] side of the [[Mont Blanc]] massif, has large white [[plagioclase]] phenocrysts, [[triclinic]] [[mineral]]s that give [[trapezium|trapezoid]] shapes when cut through)...

s of microcline

Microcline

Microcline is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of orthoclase; it is more stable at lower temperatures...

.