San Gorgonio Mountain, also known locally as Mount San Gorgonio, or Old Greyback, is the highest peak in

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...

and the

Transverse Ranges The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie within Santa B ...

at . It is in the

San Bernardino Mountains The San Bernardino Mountains are a high and rugged mountain range in Southern California in the United States. Situated north and northeast of San Bernardino and spanning two California counties, the range tops out at at San Gorgonio Mountain � ...

, east of the city of

San Bernardino San Bernardino (; Spanish language, Spanish for Bernardino of Siena, "Saint Bernardino") is a city and county seat of San Bernardino County, California, United States. Located in the Inland Empire region of Southern California, the city had a ...

and north-northeast of

San Gorgonio Pass The San Gorgonio Pass, or Banning Pass, is a elevation gap on the rim of the Great Basin between the San Bernardino Mountains to the north and the San Jacinto Mountains to the south. The pass was formed by the San Andreas Fault, a major tra ...

. It lies within the

San Gorgonio Wilderness The San Gorgonio Wilderness is located in the eastern San Bernardino Mountains, in San Bernardino County and into northern Riverside County, Southern California. It begins north of San Gorgonio Pass, approximately west of Morongo Valley and n ...

, part of the

Sand to Snow National Monument Sand to Snow National Monument is a U.S. National Monument located in San Bernardino County and northern Riverside County, Southern California. It protects diverse montane and desert habitats of the San Bernardino Mountains, southern Mojave Des ...

managed by the

San Bernardino National Forest The San Bernardino National Forest is a United States National Forest in Southern California encompassing of which are federal. The forest is made up of two main divisions, the eastern portion of the San Gabriel Mountains and the San Bernard ...

. Spanish missionaries in the area during the early 17th century named the peak after Saint Gorgonius. Since it is the highest point in a region which is separated from higher peaks (e.g. in the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

) by relatively low terrain, San Gorgonio Mountain is one of the most

topographically prominent In topography, prominence (also referred to as autonomous height, relative height, and shoulder drop in US English, and drop or relative height in British English) measures the height of a mountain or hill's summit relative to the lowest contou ...

peaks in the United States. It is ranked 7th among peaks in the 48 contiguous states and 18th overall. Like other high peaks in the Transverse Ranges, the mountain has a pyramid shape, with a steep north face and a slightly shallower south face. The mountain is large and broad; the summit plateau itself is one square-mile in area (2 km²). In contrast to its spectacular but lower neighbor,

San Jacinto Peak San Jacinto Peak (; often designated Mount San Jacinto) is a peak in the San Jacinto Mountains, in Riverside County, California. Lying within Mount San Jacinto State Park it is the highest both in the range and the county, and serves as the sout ...

, San Gorgonio is not particularly craggy, and from a distance, it appears to be an extremely high hill, earning it the name of ''greyback''. Despite not being particularly striking in appearance during the summer, it is the only mountain in Southern California with a summit a significant distance above the tree line. As such its bright white winter snow cap, unobstructed by vegetation, makes the mountain noticeable from many miles away. The mountain hosts the longest recorded line of sight in the contiguous United States; it is plainly visible from the summit of

Mount Whitney Mount Whitney (Paiute: Tumanguya; ''Too-man-i-goo-yah'') is the highest mountain in the contiguous United States and the Sierra Nevada, with an elevation of . It is in East–Central California, on the boundary between California's Inyo and Tu ...

, away.

Geography

San Gorgonio Mountain lies at the easternmost extremity of the

. The mountain is a heavily eroded, partially

dissected plateau A dissected plateau is a plateau area that has been severely eroded such that the relief is sharp. Such an area may be referred to as mountainous, but dissected plateaus are distinguishable from orogenic mountain belts by the lack of folding, me ...

.J.C. Matti and D.M. Morton, U.S. Geological Survey
Geologic setting, San Bernardino National Forest
/ref>

Big Bear Lake, California Big Bear Lake is a small city in San Bernardino County, California, located in the San Bernardino Mountains along the south shore of Big Bear Lake, and surrounded by the San Bernardino National Forest. The city is located about 25 miles (40& ...

is the largest city near San Gorgonio, and hosts two major ski resorts; it is also used for summer recreation.

Geology

The shape of the mountain is influenced by a series of steeply dipping thrust faults on the north face of the mountain. The south side of the mountain contains river canyons typical of a

. The mountain consists of a massive block of

quartz monzonite Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars. It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagiocl ...

, which sits on an ancient platform of

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...

ic rocks. Glacial and fluvial deposits dominate the surface of the lowest part of the mountain.

Hydrology

Three major Southern California rivers have their source on San Gorgonio Mountain: the

Santa Ana River The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting through ...

, the Whitewater River, and the

San Gorgonio River The San Gorgonio River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed March 16, 2011 river primarily flowing in western Riverside County, with a small upstream section in southwester ...

. Jenks Lake, on the north slope of the mountain, is one of the few perennial lakes in Southern California. San Gorgonio Mountain sits on the

Great Basin Divide The Great Basin Divide in the western United States is the ridgeline that separates the Great Basin from the Pacific Ocean watershed, which completely surrounds it. The Great Basin is the largest set of contiguous endorheic watersheds of N ...

, which separates streams that flow into the basins of the

Basin and Range Province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...

from rivers that flow into the Pacific Ocean.

Climate

The climate on most of the mountain is ''Csb'' ( Warm-summer

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

) under the

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

. The summit of San Gorgonio has an

Alpine climate Alpine climate is the typical weather (climate) for elevations above the tree line, where trees fail to grow due to cold. This climate is also referred to as a mountain climate or highland climate. Definition There are multiple definitions of ...

(''ET''), as no month in that area has an average temperature greater than .

Hiking

Like most other peaks in the Transverse Ranges, the summit is a technically easy "class 1" hike. Several trails lead to the broad summit of San Gorgonio Mountain, which rises a few hundred feet (100 m) above the

tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowp ...

. Most routes are very strenuous and require well over of elevation gain. The trail leading from the Fish Creek Trailhead to San Gorgonio Mountain has about of gain, less than the routes from the South Fork and Vivian Creek trailheads. Some junctions on this trail are not well marked.

Aircraft wreckage

On December 1, 1952, a

Douglas C-47 The Douglas C-47 Skytrain or Dakota (Royal Air Force, RAF, Royal Australian Air Force, RAAF, Royal Canadian Air Force, RCAF, Royal New Zealand Air Force, RNZAF, and South African Air Force, SAAF designation) is a airlift, military transport ai ...

, serial number 45-1124, crashed at the level on the eastern face of the mountain. The C-47 was en route from Offutt Air Force Base,

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

March Air Force Base March Air Reserve Base (March ARB), previously known as March Air Force Base (March AFB) is located in Riverside County, California between the cities of Riverside, Moreno Valley, and Perris. It is the home to the Air Force Reserve Command's Fo ...

near

Riverside, California Riverside is a city in and the county seat of Riverside County, California, United States, in the Inland Empire metropolitan area. It is named for its location beside the Santa Ana River. It is the most populous city in the Inland Empire an ...

when it struck the mountain at night in the middle of a storm. "The aircraft was last heard from at 9:51 p.m. Pacific Standard Time, Monday." Thirteen people died. Nearly one month after the C-47 accident a

Marine Corps Marines, or naval infantry, are typically a military force trained to operate in littoral zones in support of naval operations. Historically, tasks undertaken by marines have included helping maintain discipline and order aboard the ship (refl ...

HRS-2 helicopter, bureau number 129037, crashed on the mountain in coordination of the efforts of recovering the victims. The three crewmen of the helicopter survived the impact. The remains of the wreckage of the two aircraft were left on the mountain and are accessible via the Fish Creek Trailhead or the South Fork Trailhead. In more recent years, the mountain claimed the lives of

Frank Sinatra Francis Albert Sinatra (; December 12, 1915 – May 14, 1998) was an American singer and actor. Nicknamed the "Honorific nicknames in popular music, Chairman of the Board" and later called "Ol' Blue Eyes", Sinatra was one of the most popular ...

's mother, Dolly (January 6, 1977) and

Dean Paul Martin Dean Paul Martin Jr. (born Dino Paul Crocetti Jr., November 17, 1951 – March 21, 1987) was an American pop singer and film and television actor. A member of the California Air National Guard, Martin died in a crash during a military training f ...

(March 21, 1987), son of

Dean Martin Dean Martin (born Dino Paul Crocetti; June 7, 1917 – December 25, 1995) was an American singer, actor and comedian. One of the most popular and enduring American entertainers of the mid-20th century, Martin was nicknamed "The King of Cool". M ...

, in unrelated plane crashes. Martin was an

Air National Guard The Air National Guard (ANG), also known as the Air Guard, is a federal military reserve force of the United States Air Force, as well as the air militia of each U.S. state, the District of Columbia, the Commonwealth of Puerto Rico, and the ter ...

pilot; the McDonnell Douglas F-4C he was flying disappeared in a snowstorm and the wreckage was found on the mountain several days later.

References

External links

* *
OnTheTrail.org
- San Gorgonio Topo and Trail Map {{authority control San Bernardino Mountains Mountains of San Bernardino County, California Sand to Snow National Monument San Bernardino National Forest North American 3000 m summits Mountains of Southern California San Gorgonio Pass