The San Bernardino National Wildlife Refuge is located on the U.S.-Mexico border in Cochise County, Arizona. Situated at elevation in the bottom of a wide valley, the refuge encompasses a portion of the headwaters of the

Yaqui River The Yaqui River (Río Yaqui in Spanish) (Hiak Vatwe in the Yaqui or Yoreme language) is a river in the state of Sonora in northwestern Mexico. It was formerly known as the Rio del Norte. Being the largest river system in the state of Sonora, th ...

, which drains primarily western Chihuahua and eastern Sonora, Mexico. The

ranch A ranch (from es, rancho/Mexican Spanish) is an area of land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of a farm. These terms are most ofte ...

was acquired by the

U.S. Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...

in 1982 to protect the water resources and provide

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

for endangered native fishes.Refuge profile
/ref>Refuge website
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Geography

This area is part of the

basin and range Basin and range topography is characterized by alternating parallel mountain ranges and valleys. It is a result of crustal extension due to mantle upwelling, gravitational collapse, crustal thickening, or relaxation of confining stresses. The e ...

geologic region, characterized by linear mountain ranges which are separated by broad, flat basins. The region was impacted by relatively recent

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

activity, leaving

volcanic plug A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged ma ...

s and cinder cones visible throughout the

San Bernardino Valley (Arizona) The San Bernardino Valley of Arizona is a northeast-by-southwest trending valley in extreme southeast Cochise County, Arizona. The north end of the valley merges into the northwest-by-southeast trending San Simon Valley; both merge in western pe ...

Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s have further altered the region and helped allow the flow of many springs and seeps. All of these dynamic geological events have played major roles in shaping the valley, catching and storing crucial water, and helping determine the variety of plants and animals present.

History

The San Bernardino Valley once supported permanently flowing creeks, springs, and marshy wetlands. The giant sacaton grassland in the valley has been described as "a luxuriant meadow some eight or ten miles long and a mile wide." The dependable source of water and grass made the area not only invaluable to a huge diversity of fish and wildlife, but also a center of human activity for centuries. With expanding settlement beginning in the late 19th century came

farming Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic ...

, and

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animal ...

production, all of which competed for the same water. While the extensive

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

s here once provided historic habitat for eight different kinds of native fish, the lowering water table led to severe changes in the habitat and the eventual local extinctions of many species. The San Bernardino National Wildlife Refuge was established in 1982 as part of a novel approach of rescuing these species; manmade

artesian wells An artesian aquifer is a confined aquifer containing groundwater under positive pressure. An artesian aquifer has trapped water, surrounded by layers of impermeable rock or clay, which apply positive pressure to the water contained within th ...

connected to the aquifer that could host the endangered fish being threatened by the draining of their habitats.

Ecology

The refuge protects several endangered species of fish

endemic Endemism is the state of a species being found 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 found else ...

to the

's watershed that reach their northernmost limits at the refuge. As the Yaqui River primarily flows through

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, the refuge is also the only area in the United States where these fish are found. The fish include the Yaqui chub (''Gila purpurea''), beautiful shiner (''Cyprinella formosa''), Yaqui catfish (''Ictalurus pricei''), Yaqui topminnow (''Poeciliopsis sonoriensis),''

Yaqui longfin dace The Yaqui longfin dace is a small fish of the American Southwest and northern Mexico, and considered a form of the longfin dace. It is often referred to as ''Agosia chrysogaster'' sp 1. Description The Yaqui longfin dace is similar to the Gil ...

(''Agosia chrysogaster'' sp 1), and Mexican stoneroller (''Campostoma ornatum''). The former four species are considered federally

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

within the United States and are protected by the Endangered Species Act. Other rare, range-limited species known from the refuge include the Cochise pincushion cactus (''Escobaria robbinsiorum'') Huachuca water umbel (''Lilaeopsis schaffneriana''), San Bernandino springsnail (''Pyrgulopsis bernandina''), and

Chiricahua leopard frog The Chiricahua leopard frog (''Lithobates chiricahuensis'' syn. ''Rana chiricahuensis'') is a species of frog in the family Ranidae, the true frogs. Distribution and habitat It is native to Mexico and the United States (Arizona and New Mexico) ...

(''Lithobates chiricahuensis'').

Threats

Construction of the

Trump wall The Trump wall, commonly referred to as "The Wall", is an expansion of the Mexico–United States barrier that started in the U.S. during the 1980’s to keep help enforce immigration laws in the United States. Prior to Donald Trump, border ...

cut through a migration corridor for the jaguar. It will likely stop the migration of jaguars and other animals between Mexico and the US. From late 2019 onwards, massive amounts of water have been pumped from the aquifer for the wall's construction, causing likely permanent damage to the natural water flow in the area. Declassified emails released in mid 2020, dating back to the beginning of the wall's construction in fall 2019, found that water extraction for the wall drained several of the refuge's crucial

, forcing evacuations of the endangered fish in them. Large-capacity water pumps had to be purchased and installed in order to mimic the natural pond outflow lost by the water extraction. Refuge manager Bill Radke has referred to the wall's construction as the “current greatest threat to endangered species in the southwest region”.

References

External links