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The VERDUGO MOUNTAINS is a small, rugged mountain range of the Transverse Ranges system, located just south of the western San Gabriel Mountains in Los Angeles County , Southern California . The range is sometimes known as the VERDUGO HILLS or simply the VERDUGOS.

Surrounded entirely by urban development, the Verdugo Mountains represent an isolated wildlife island and are in large part under public ownership in the form of undeveloped parkland. The mountains are used primarily for recreation in the form of hiking and mountain biking, and as the site of communications installations on the highest peaks.

The mountains appear to be low-lying to local residents; however, there are a number of rugged sections, and the high portion of range reaches nearly as high as the nearby Santa Susana Mountains .

CONTENTS

* 1 Geography * 2 Geology * 3 Flora, fauna and climate

* 4 History

* 4.1 Glendale at their southeastern end the Verdugo Mountains are separated from the San Rafael Hills by the Verdugo Wash .

The highest summit is the informally named Verdugo Peak (3,126 feet ), located near the center of the range and rising to approximately 2,200 feet (670 m) above its southern base. Other peaks include Tongva Peak (2,656 feet ), recently named in honor of the Tongva (Gabrielino) people, the original inhabitants of much of the Los Angeles Basin , Santa Monica Mountains , and San Gabriel Valley areas. Other informally named peaks are Mount La Tuna on the north end and Mount Thom on the south end of the range. With the exception of Mount La Tuna, all these summits, as well as several others, are occupied by communications towers.

The Verdugo Mountains lie within the corporate boundaries of the cities of Glendale , Burbank , and Los Angeles . The neighborhood of La Crescenta , most of which lies within Glendale, is adjacent to its northern end, as are the Los Angeles neighborhoods of Tujunga, Sunland , Shadow Hills , and Sun Valley (the last of which includes La Tuna Canyon).

GEOLOGY

The Verdugo Mountains consist of an east-west-trending antiformal fault block , bounded on south by the Verdugo Fault, a north-dipping reverse fault , and on the north by the Sierra Madre thrust fault near the front of the San Gabriel Mountains, thus including the sediment-covered Crescenta Valley within the Verdugo Mountains Block. The Verdugo Fault lies slightly south of the topographic range front and is completely covered by sediments.

The rocks within the Verdugo Mountains block are almost entirely igneous and metamorphic rocks similar to the crystalline basement rocks exposed to the north in that portion of the San Gabriel Mountains south of the San Gabriel Fault. These rocks consist of gneiss , and gneissic diorite and quartz diorite , intruded by irregular bodies of equigranular granitic rocks, predominantly quartz diorite and granodiorite , with accompanying pegmatite and aplite . Exposed rocks in the Shadow Hills neighborhood at the extreme northwestern end of the Verdugos are typically marine sedimentary rocks of Miocene age, predominantly sandstone and shale .

The Verdugo Mountains are part of the western Transverse Ranges , which have risen in the last 7 million years as the result of contractional deformation resulting from transpressional motion and rotation of crustal blocks in the "Big Bend" region of the San Andreas Fault . The amount of crustal shortening since the beginning of the Pliocene has been estimated to be on the order of 7 kilometers (4.3 mi). The Verdugo fault and Sierra Madre thrust are part of a complex system of faults that accommodate some of this shortening and generally become younger to the south, with the Verdugo Fault possibly being the youngest member of this system and forming the current boundary between this portion of the western Transverse Ranges and the Los Angeles basin. Uplift along the Verdugo fault may total approximately 2.5 km (1.6 mi), at a minimum rate of 1.1 km (0.68 mi) per million years since 2.3 million years ago, moving the crystalline rocks of the Verdugo Mountains up and over younger Tertiary and Quaternary sediments to the south. The Verdugo Mountains are, therefore, young and rapidly rising, reflected in their steep topography and rapid rates of erosion.

FLORA, FAUNA AND CLIMATE

See also: California chaparral and woodlands

The Verdugo Mountains lie almost entirely within the chaparral plant community, as defined by Munz and later authors, including Sawyer _et al._ This dense, shrub-dominated community of the California chaparral and woodlands is more highly developed on the north-facing slopes than on the drier, hotter south-facing slopes. Among the shrub species that characterize this community, prominent in the Verdugos are laurel sumac (_ Malosma laurina _), toyon (_Heteromeles arbutifolia _), poison oak (_ Toxicodendron diversilobum _), chamise (_Adenostoma fasciculatum _) and two species of California-lilac (_Ceanothus crassifolius _ and _ Ceanothus oliganthus _). Native trees are restricted to protected canyons and sites along the largely seasonal watercourses. Coast live oak (_ Quercus agrifolia _), California bay laurel (_Umbellularia californica_), California sycamore (_Platanus racemosa _), California walnut (_ Juglans californica _), and several species of willow (_ Salix _ spp.) are the most common. Non-native trees, particularly pines (_ Pinus _ spp.), cypress (_ Cupressus _ spp.), locust (_ Robinia pseudoacacia _), and Australian eucalyptus (_ Eucalyptus _ spp.) have been planted locally along the fire roads and, most notably, in the Fire Warden's Grove, established in the wake of a wildfire in 1927.

Except for a tenuous link to the large wild area in the San Gabriel Mountains through Big Tujunga Wash at their northwestern end, the Verdugo Mountains are an urban wildlife island completely surrounded by development. Among the large mammals, coyote (_ Canis latrans _) and mule deer (_ Odocoileus hemionus _) are the most common; mountain lions (_ Puma concolor _) and black bears (_ Ursus americanus _) have occasionally been reported. The many rodent species support a population of western rattlesnakes (_ Crotalus viridis _). Of the numerous bird species present, the most characteristic of the chaparral here, and throughout California, is the small, seldom seen but often heard wrentit (_ Chamaea fasciata _). With its call of three or four chirps followed by an accelerating trill, often likened to the sound of a dropped ping-pong ball, the wrentit provides the most characteristic sound of the chaparral.

The Verdugo Mountains have warm, dry summers and cool wet winters. Snow infrequently falls along the crest during the coldest winter storms, but melts rapidly. Annual precipitation varies from about 18 inches at the base to about 25 inches at the crest. Most of the rain falls between November and March during periodic frontal passages.

HISTORY

The mountains were part of the indigenous Tongva people's homelands for over 7,000 years, with villages at some springs in the canyons.

The Verdugo Mountains were named for Jose Maria Verdugo, holder of the Rancho San Rafael land grant , which covered the mountains during California's Spanish and Mexican periods . On October 20, 1784 Pedro Fages , the military governor of Alta California , granted Jose Maria Verdugo permission to use the rancho, known officially by the name San Rafael but informally called "La Zanja" by Verdugo. The rancho's boundaries were primarily defined by the Verdugo Mountains, the Arroyo Seco and the Los Angeles River , with the boundary following north along the east bank of the river and wrapping westerly around Griffith Park to a point near the Travel Town Museum in the park.

GLENDALE & MOUNT VERDUGO RAILWAY

One of the earliest attempts to access and develop the interior of the Verdugo Mountains was the 1912 proposal by Colonel Lewis Ginger to build a cable incline railroad to the summit of Mount Verdugo, now known as Mount Thom. The proposed Glendale ">

* ^ "Verdugo Mountains". _ Geographic Names Information System _. United States Geological Survey . Retrieved 2009-05-04. * ^ _A_ _B_ Arkle, Jeanette, C, and Armstrong, Phillip A. (2007). " Quaternary exhumation of the Verdugo Mountains, Los Angeles Basin, constrained by low-temperature thermochronometry." Geological Society of America _Abstracts with Programs,_ vol. 39, no. 6, p. 83. * ^ Weber, F. Harold, Jr., and others (1980). Earthquake Hazards Associated with the Verdugo-Eagle Rock and Benedict Canyon Fault Zones, Los Angeles County California. Calif. Div. Mines and Geology Open File Report 80-10 * ^ Luyendyk, B. P. (1991). "A model for Neogene crustal rotations, transtension, and transpression in southern California". _Geological Society of America Bulletin,_ vol. 103, pp.1528-1536. * ^ Schneider; C. L., Hummon, C.; Yeats, R. S.; and Huftile, G.J. (1996). "Structural evolution of the northern Los Angeles basin, California, based on growth strata." _Tectonics,_ vol. 15, pp. 341-355. * ^ Arkle, Jeanette C.; and Armstrong, Phillip A. (2009). "Exhumation of the Verdugo Mountains, Southern California; constraints from low-temperature thermochronology and geomorphic analysis." Geological Society of America _Abstracts with Programs,_ vol. 41, no. 67 p. 300. * ^ Meigs, Andrew; Yule, Doug; Blythe, Ann; and Burbank, Doug (2003). "Implications of disturbed crustal deformation for exhumation in a portion of a transpressional plate boundary, Western Transverse Ranges, Southern California." _ Quaternary International,_ vol. 101-102, pp.169-177. * ^ Munz,Phillip A., in collaboration with David D. Keck (1968). _A California Flora and Supplement. Berkeley: University of California Press._ * ^ Sawyer, J., and Keeler-Wolf, T. (1995). _A Manual of California Vegetation._ Sacramento: California Native Plant Society. * ^ Groves, Martha (May 29, 2015). "Meet the Verdugo Mountains\' very own mountain lion: P-41". _ Los Angeles Times _. * ^ Tchekmedyian, Alene (July 8, 2016). "Bear spotted at Burbank golf course". _ Burbank Leader _. * ^ Quinn, Ronald D., and Keeley, Sterling C. (2006) _Introduction to California Chaparral._ Berkeley: University of California Press. * ^ Gumprecht, Blake. The Los Angeles River: Its Life, Death, and Possible Rebirth, Johns Hopkins University Press, 1999, ISBN 0-8018-6642-1 , page 31 * ^ _A_ _B_ Kielbasa, John R. (1998). _Historic Adobes of Los Angeles County_. Pittsburg : Dorrance Publishing Co. ISBN 0-8059-4172-X . . * ^ Duke, Donald (1998). _Incline Railways of Los Angeles and Southern California_. San Marino CA: Golden West Books. * ^ Barbour , Michael, Keeler-Wolf , Todd, and Schoenherr, Allan A. (2007). _Terrestrial Vegetation of California ,_ 3rd ed. Berkeley: University of California Press. * ^ Quinn, Ronald D., and Keeley, Sterling G. (2006). _Introduction to California Chaparral._ Berkeley: University of California Press. * ^ Carle, David (2008). _Introduction to Fire in California._ Berkeley: University of California Press. * ^ "The 1927 Burbank Canyon Fire". _Burank Fire Department website (former posting)_. Retrieved 12 February 2011. * ^ _A_ _B_ "The 1955 La Tuna Canyon Fire". _ Los Angeles Fire Department Historical Archive_. Retrieved 12 February 2011. * ^ _A_ _B_ Boucher, David, 1991. _Ride the Devil Wind: a History of the Los Angeles County Forester ">(PDF). _Glendale Fire and Rescue News_. October 2002. Retrieved 12 February 2011. * ^ "Southern California Wildfires 2005". _Wildfire.com: the Home of the Wildland Firefighter_. Retrieved 12 February 2011. * ^ "Rim of the Valley Corridor Special Resource Study". National Park Service. Retrieved 2014-12-30. * ^ Kamal, Sameea (March 4, 2015). "Three lawmakers urge Park Service action on Rim of the Valley study". _ Los Angeles Times_. * ^ McKinney, John (1994). _Walking Los Angeles_ New York: HarperCollinsWest.

FURTHER READING

* _Tectonics of the San Gabriel Basin and surroundings, southern California_. Robert S. Yeats. Corvallis, Oregon : Oregon State University , Department of Geosciences, 2004. * _ Los Angeles River: Its Life, Death, and Possible Rebirth_. Blake Gumprecht. Baltimore & London : The Johns Hopkins University Press, 1999. ISBN 0-8018-6642-1 . * _Afoot "> * Burbank, California, 7.5 minute topographic quadrangle map