Black Mountain Open Space Park is a city park located in the suburbs of

San Diego, California San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States ...

Description

The park covers in the Black Mountain Ranch and

Rancho Peñasquitos Rancho or Ranchos may refer to: Settlements and communities *Rancho, Aruba, former fishing village and neighbourhood of Oranjestad *Ranchos of California, 19th century land grants in Alta California **List of California Ranchos *Ranchos, Buenos Ai ...

area of northern San Diego. The park offers numerous trails for hiking and biking, and boasts a variety of native animal and plant species.

Plant species

Native plant species preserved in Black Mountain Open Space Park include both

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

and

coastal sage scrub Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is w ...

. Native to the east and north sides of the mountain, the chaparral community includes

manzanita Manzanita is a common name for many species of the genus ''Arctostaphylos''. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from Southern British Columbia and Washington to Or ...

, laurel sumac, lemonade berry,

coffee berry Coffee berry may refer to: * Coffee cherry, the fruit of coffee plants * ''Frangula californica'', or California coffeeberry, a plant in the buckthorn family, native to western North America * ''Frangula rubra'', or Sierra coffeeberry, another pl ...

chamise ''Adenostoma fasciculatum'', commonly known as chamise or greasewood, is a flowering plant native to California and Baja California. This shrub is one of the most widespread plants of the California chaparral ecoregion. Chamise produces a specia ...

toyon ''Heteromeles arbutifolia'' (; more commonly by Californian botanists), commonly known as toyon, is a common perennial shrub native to extreme southwest Oregon, California, and the Baja California Peninsula. It is the sole species in the genus ...

, and California lilac. The coastal sage scrub, native to the south and west faces of the mountain, include

white White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White on ...

and black sage,

California sagebrush ''Artemisia californica'', also known as California sagebrush, is a species of western North American shrub in the sunflower family. Description ''Artemisia californica'' branches from the base and grows out from there, becoming rounded; it gro ...

California buckwheat ''Eriogonum fasciculatum'' is a species of wild buckwheat known by the common names California buckwheat and flat-topped buckwheat. Characterized by small, white and pink flower clusters that give off a cottony effect, this species grows vari ...

, and California sunflower.

Animal species

The Black Mountain Open Space Park is home to a wide variety of animal species. Mammals include

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whit ...

bobcat The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the IUC ...

desert woodrat The desert woodrat (''Neotoma lepida'') is a species of pack rat native to desert regions of western North America. Description Desert woodrats are relatively small for pack rats, measuring in length, including a tail. They weigh from , wi ...

, and Pacific kangaroo rat, and many others. Among the more than 80 birds species that can be found in the park, rare birds like the

California gnatcatcher The California gnatcatcher (''Polioptila californica'') is a small long insectivorous bird which frequents dense coastal sage scrub growth. This species was recently split from the similar black-tailed gnatcatcher of the Sonoran and Chihuahuan d ...

rufous-crowned sparrow The rufous-crowned sparrow (''Aimophila ruficeps'') is a small American sparrow. This passerine is primarily found across the Southwestern United States and much of the interior of Mexico, south to the transverse mountain range, and to the Pa ...

, and

northern harrier The northern harrier (''Circus hudsonius''), or ring-tailed hawk, is a bird of prey. It breeds throughout the northern parts of the northern hemisphere in Canada and the northernmost USA. The northern harrier migrates to more southerly areas ...

reside in the area. Reptiles include the

red diamond rattlesnake :''Common names: red diamond rattlesnake, red rattlesnake, red diamond snake,Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. . more'' ''Crotalus ruber'' is a venomous pit viper speci ...

and amphibians include the

Pacific chorus frog The Pacific tree frog (''Pseudacris regilla''), also known as the Pacific chorus frog, has a range spanning the Pacific Northwest, from Northern California, Oregon, and Washington to British Columbia in Canada and extreme southern Alaska. They l ...

and

slender salamander ''Batrachoseps'' is a genus of lungless salamanders (plethodontids) often called slender salamanders. They can be distinguished from other lungless salamanders by the four toes they have on each foot. Their genus name ''Batracho-seps'' means "f ...

Black Mountain

Black Mountain is the central feature of Black Mountain Open Space Park, standing at 1,554 feet (474 m) tall. At its peak, Black Mountain is host to a handful of communication towers, including a retired AT&T microwave repeater tower and a Verizon wireless communication facility. Prior to European contact, the

Kumeyaay The Kumeyaay, also known as Tipai-Ipai or by their historical Spanish name Diegueño, is a tribe of Indigenous peoples of the Americas who live at the northern border of Baja California in Mexico and the southern border of California in the Unit ...

lived on the mountain and referred to it as "Amat Kwanyil". The mountain is also an extinct volcano, having last erupted 118-125 million years ago. Black Mountain is a part of the

Santiago Peak Santiago Peak is the southern mountain of the Saddleback landform in Orange County, California. It is the highest and most prominent peak of both the Santa Ana Mountains and Orange County; it also marks a border point with Riverside County. Th ...

Volcanoes, including

Cowles Mountain Cowles Mountain (/koʊlz/, aʊlz properly ''KOHLZ'', commonly ''KOWLZ'') is a prominent mountain located in the San Carlos neighborhood, within the city limits of San Diego. The summit is the highest point of the city of San Diego. It is prote ...

, which are a group of volcanoes that originated as a chain of volcanic islands 150 million years ago.

Mine

Tucked away in the Black Mountain canyon is an abandoned arsenic mine, accessible via pathways branching off of the park's Miner's Ridge Loop trail. The mine was established in the 1920s by Escondido rancher, rodeo cowboy, and actor Frank Hopkins, due to the demand for

white arsenic Arsenic trioxide, sold under the brand name Trisenox among others, is an inorganic compound and medication. As an industrial chemical, whose major uses include in the manufacture of wood preservatives, pesticides, and glass. As a medication, i ...

, a key ingredient in pesticides that attacked infesting

boll weevil The boll weevil (''Anthonomus grandis'') is a beetle that feeds on cotton buds and flowers. Thought to be native to Central Mexico, it migrated into the United States from Mexico in the late 19th century and had infested all U.S. cotton-growing ...

s. As the boll weevil population shrank, the demand for white arsenic fell, causing the abandoning of the mine in 1927. According to a 1939 article, published in the Vista Press, Hopkins also used this mine to find

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

. In 2016, the University of San Diego conducted soil sampling in the vicinity of the mine site. Some locations, including portions of the Miner's Ridge Loop trail revealed high levels of arsenic present. As of January 6, 2017 the San Diego City Attorney recommended closure of the lower sections of the trail pending further study. The Jas Arnold Trail for All People (located at the Miner's Ridge Loop parking lot), a handicapped accessible trail named in honor of the park's long serving Chair of the Citizen's Advisory Committee who passed in May 2016 remains open to the public. The Lilac Canyon Trail which connects this same parking lot to the Glider Port also remains open.

Hiking

The park is a popular hiking spot, offering numerous trails of varying length and difficulty.

Trails

*Lusardi Creek Loop Trail *East Rim Trail *Miner's Ridge Loop Trail **2.3 miles with 670 feet of climbing ** Accessible via Carmel Valley Rd. *Glider Point Trail *Nighthawk Trail ** Accessible via Hilltop Community Park *Little Black Loop Trail *South Point View Trail