Agua Tibia Wilderness (ATW) is a protected area in Riverside and

San Diego San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

counties, in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. It is mostly within the Palomar Ranger District of the

Cleveland National Forest Cleveland National Forest is a National forest (United States), U.S. national forest in Southern California that encompasses 460,000 acres/ of inland Montane ecosystems, montane regions. It is approximately 60 miles from the Pacific Ocean, withi ...

. The area was originally protected as the Agua Tibia Primitive Area until January 1975 when it was added to the

National Wilderness Preservation System The National Wilderness Preservation System (NWPS) of the United States protects federal government of the United States, federally managed Wilderness, wilderness areas designated for preservation in their natural condition. Activity on formally ...

with the passage of

Public Law Public law is the part of law that governs relations and affairs between legal persons and a government, between different institutions within a state, between different branches of governments, as well as relationships between persons that ...

93-632 by the

United States Congress The United States Congress is the legislature, legislative branch of the federal government of the United States. It is a Bicameralism, bicameral legislature, including a Lower house, lower body, the United States House of Representatives, ...

. Between its inception and 1984, the ATW was San Diego County's only officially designated wilderness area. The Spanish name, Agua Tibia, translates as ''warm water''. Its approximate boundaries are: * North – SR 79 * East – Arroyo Seco River * South – Fray Creek * West – Pala Road

Environment

There are no permanent streams in the ATW. The highest landform is Agua Tibia Mountain with an elevation of . Though the summer climate is hot, with limited shade and no water sources, there were no fires in the ATW for 110 years. In the last two decades, there have been four fires including the

Palomar Mountain Palomar Mountain ( ; ) is a mountain ridge in the Peninsular Ranges in northern San Diego County, California. It is known as the location of Palomar Observatory and Hale Telescope, and known for Palomar Mountain State Park. History The Luise� ...

Fire (1987), the Vail Fire (1989), the Agua Tibia Fire (2000), and the Poomacha Fire (2007). Its pollution exposure is monitored within the

Air Basin.

Flora

The Agua Tibia Wilderness is home to rare and

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

plants. These include: * Nevin's barberry ('' Berberis nevinii'') * Rainbow manzanita ('' Arctostaphylos rainbowensis'') * Vail Lake ceanothus ('' Ceanothus ophiochilus'')

Agua Tibia Research Natural Area

The Agua Tibia Research Natural Area (ATRNA), located within the wilderness, comprises of bigcone Douglas-fir—canyon live oak forest. The area was set aside for the study of this forest type in the Peninsular Range province and with emphasis on forest succession, long-range ecological changes and the effects of resource management practices. Bigcone Douglas-fir (''

Pseudotsuga macrocarpa ''Pseudotsuga macrocarpa'', commonly called the bigcone spruce or bigcone Douglas-fir, is an evergreen conifer native to the mountains of southern California. It is notable for having the largest (by far) cones in the genus ''Pseudotsuga'', henc ...

'') is a

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

species and is

to Southern California. This population on the ATRNA is unique for its relatively great age, size, genetic purity, placement near the southern extent of the species' range, and for its remoteness and lack of disturbance by man. Other notable plants in the research area are Laguna linanthus ('' Linanthus orcuttii ssp. pacificus'') and Hall's monardella ('' Monardella macrantha ssp. hallii''). Both are listed as 1B by the

California Native Plant Society The California Native Plant Society (CNPS) is a California environmental non-profit organization (501(c)(3)) that seeks to increase understanding of California's native flora and to preserve it for future generations. The mission of CNPS is to c ...

's Rare Plant Program.

Springs

According to a U.S. government geologist writing in 1915, "Near the southern base of Agua Tibia Mountain and 25 miles in a direct line north of west from Warner Hot Springs, warm water (''agua tibia''), issues along a

fault zone In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic f ...

that is parallel to the one in Warner Valley. The water rises with a temperature of in a marshy area that covers perhaps an acre. It is conducted from a board-curbed pool to tubs in a near-by house, for bathing and laundry use. Bubbles continually rise in the pool and the water is distinctly sulphureted...This water is essentially primary saline in character, being a soft water of moderate mineralization."

References

External links

USDA Forest Service official site

Topo Map

Land Management Plan Strategy

Agua Tibia Wilderness
{{Authority control Wilderness areas of California Cleveland National Forest Protected areas of Riverside County, California Protected areas of San Diego County, California Natural history of the Peninsular Ranges Protected areas established in 1975 1975 establishments in California Springs of San Diego County, California