The Verdugo Mountains, also known as the Verdugo Hills or simply The Verdugos, are a small, rugged mountain range of the Transverse Ranges system in Los Angeles County, California. Located just south of the western San Gabriel Mountains, the Verdugo Mountains region incorporates the cities of Burbank, Glendale, Pasadena, and La Cañada Flintridge; the unincorporated communities of Altadena and La Crescenta-Montrose; as well as the City of Los Angeles neighborhood of Sunland-Tujunga. It is where the borders of the San Gabriel Valley and the San Fernando Valley meet.
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 arise directly from the eastern floor of the San Fernando Valley, exaggerating their height from some vantages. Beginning with foothills, they rapidly rise to rugged sections, with the highest peaks topping .
Geography The northwest-trending range is approximately long by wide, and roughly parallels the southern front of the San Gabriel Mountains at a distance of to , with the Crescenta Valley lying between the two. The southern front of the range forms part of the northeastern boundary of the San Fernando Valley; at their southeastern end the Verdugo Mountains are separated from the San Rafael Hills by the Verdugo Wash.
The highest summit at is the informally named Verdugo Peak, located near the center of the range and rising to approximately above its southern base. Other peaks include Tongva Peak , 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 the range's 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 the 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,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. 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 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 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.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 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.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. The amount of crustal shortening since the beginning of the Pliocene has been estimated to be on the order of . 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.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. Uplift along the Verdugo fault may total approximately , at a minimum rate of per million years since 2.3 million years ago,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. 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.
Municipalities and neighborhoods
Source:
Incorporated cities (independent)
Glendale Pasadena La Cañada Flintridge Burbank
Unincorporated communities
Altadena La Crescenta-Montrose
Neighborhoods in the City of Los Angeles
Sunland-Tujunga
Flora, fauna and climate
The Verdugo Mountains lie almost entirely within the chaparral plant community, as defined by MunzMunz, Phillip A., in collaboration with David D. Keck (1968). A California Flora and Supplement. Berkeley: University of California Press. and later authors, including Sawyer et al.Sawyer, J., and Keeler-Wolf, T. (1995). A Manual of California Vegetation. Sacramento: California Native Plant Society. 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, especially on the shadier north slope of the range, where soil moisture levels are higher. 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 native trees. 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).Quinn, Ronald D., and Keeley, Sterling C. (2006) Introduction to California Chaparral. Berkeley: University of California Press. 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 average precipitation increases with elevation (due to the orographic lift effect), from 17–21 inches at the base to about 24–28 inches at the crest. Annual rainfall totals are highly variable from year to year, with the higher totals usually in El Nino years. 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.Gumprecht, Blake. The Los Angeles River: Its Life, Death, and Possible Rebirth, Johns Hopkins University Press, 1999, , page 31 The village of Wikangna was located in the area, possibly located at what is now the Verdugo Hills Golf Course.
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, The proposed Glendale & Verdugo Mountain Railway was to run in a straight line from the Pacific Electric's Casa Verdugo station at the top of Brand Boulevard to the summit of Mount Verdugo, employing cars with stepped seating similar to those of Angels Flight on Bunker Hill in Los Angeles.Duke, Donald (1998). Incline Railways of Los Angeles and Southern California. San Marino CA: Golden West Books. Initially, Colonel Ginger had proposed that his cable railway would lift a Pacific Electric car directly to the summit, but Henry E. Huntington did not approve of this scheme. The railway was to have four or five stations along the incline and a large visitor center at the summit. Several months after the initial proposal, the route was altered to run up the west side of Verdugo Canyon from a hoped-for extension of the Pacific Electric up Verdugo Canyon to Montrose. Interest in the cable railway continued for about a year, but the project was abandoned before a company could be formed, largely as the result of the Pacific Electric's decision not to build the Montrose extension.
Wildfire