Jewel Cave National Monument
Jewel Cave National Monument contains Jewel Cave the third longest cave in the world, with 200.3 miles of mapped passageways. It is located 13 miles west of the town of Custer in Black Hills of South Dakota, it became a national monument in 1908. Frank and Albert Michaud, two local prospectors, discovered the cave in 1900, when they felt cold air blowing out of a small hole in a canyon, it is unknown whether any previous inhabitants of the area were aware of the natural cave opening, not large enough for a person to enter. After enlarging the cave entrance with dynamite, the Michaud brothers found a cavern lined with calcite crystals, which led them to name it "Jewel Cave." The brothers tried to capitalize on the discovery, widening the opening, building walkways inside, opening it to tourists. Although their venture was unsuccessful, news of the discovery reached Washington. President Theodore Roosevelt proclaimed Jewel Cave a National Monument on February 7, 1908; the area around the natural entrance to the cave was further developed by the Civilian Conservation Corps in the 1930s.
The National Park Service assumed management of the monument in 1933 and began offering tours in 1939. As as 1959, less than 2 miles of passageway had been discovered; that year, however and Jan Conn, local rock climbers, began exploring, within two years had mapped 15 miles. Much of the new discoveries lay outside the boundaries of the monument, under land managed by the United States Forest Service; the two agencies performed a land swap in 1965, establishing the present boundaries of the park, enabling the development of a new part of the cave. The Park Service sunk a 300 feet elevator shaft to a remote cave area, built concrete walks and metal stairs and platforms along a one-half-mile loop; the "Scenic Tour" was opened in 1972. Most modern-day visitors tour that part of the cave. In August 2000, an 83,000 acres forest fire burned 90 % of the surrounding area; the visitor center and historic buildings were spared. By 1979, Herb and Jan Conn had discovered and mapped more than 64 miles of passages.
Although they retired from caving by the early 1980s, exploration has continued unabated. Because the areas being explored take many hours to reach, explorers now sometimes camp in the cave during expeditions of as long as four days; the cave is mapped by traditional survey techniques, using compass and today with lasers instead of tape measures. Its 198.00 mi of mapped passageway make Jewel Cave the third longest cave in the world, after Mammoth Cave System in Kentucky and Sistema Sac Actun at the Yucatán Peninsula, at 198 mi. The discovered areas in the cave account for only about 3 to 5% of the estimated total air volume of the cave; the cave volume is estimated by measuring the amount of air that the cave "exhales" when the outside air pressure drops and "inhales" when the outside air pressure rises. Jewel Cave is a "breathing cave," which means air enters or exits the cave with changes in atmospheric pressure from day to night or due to changes in the weather; this was first explained by Herb Conn in 1966.
Most of the cave formed within the Mississippian Pahasapa Limestone deposited 350 million years ago. The limestones and shales deposited in these Paleozoic and Mesozoic seas were eroded with the geologic uplift associated with Laramide Orogeny and the formation of the Black Hills; the main passages of the cave formed in the early Cenozoic. Uplift continued in the Late Pliocene or Early Pleistocene lowering the water table and draining the cave. Jewel Cave passages follow a pattern of joint development; the faults and joints are associated with the uplift of the Black Hills 58 to 54 million years ago. After main cave dissolution, a thick layer of calcite lined the walls about 2.5 million years ago. During cave development and afterwards and speleogens formed, including the "jewels" or spar. Other examples include stalactites, flowstone, cave popcorn, helictites, conulites, cave pearls, rafts, rims and frostwork; the gypsum formations include needles, cotton, hair and spiders. Jewel Cave contains a rare formation called a hydromagnesite balloon.
Those are created when gas of an unknown source inflates a pasty substance formed by the precipitation of the magnesium carbonate hydroxide mineral. Jewel Cave is open year round; the Park Service offers three tours: the scenic tour, a half-mile loop through a paved and lighted central portion of the cave accessible by elevator. There are 3 surface trails varying in difficulty. List of caves List of longest caves in the United States Wind Cave National Park Mammoth Cave National Park Lehman Caves Oregon Caves National Monument Russell Cave National Monument Timpanogos Cave National Monument Speleology
National Historic Landmark
A National Historic Landmark is a building, object, site, or structure, recognized by the United States government for its outstanding historical significance. Of over 90,000 places listed on the country's National Register of Historic Places, only some 2,500 are recognized as National Historic Landmarks. A National Historic Landmark District may include contributing properties that are buildings, sites or objects, it may include non-contributing properties. Contributing properties may or may not be separately listed. Prior to 1935, efforts to preserve cultural heritage of national importance were made by piecemeal efforts of the United States Congress. In 1935, Congress passed the Historic Sites Act, which authorized the Interior Secretary authority to formally record and organize historic properties, to designate properties as having "national historical significance", gave the National Park Service authority to administer significant federally owned properties. Over the following decades, surveys such as the Historic American Buildings Survey amassed information about culturally and architecturally significant properties in a program known as the Historic Sites Survey.
Most of the designations made under this legislation became National Historic Sites, although the first designation, made December 20, 1935, was for a National Memorial, the Gateway Arch National Park in St. Louis, Missouri; the first National Historic Site designation was made for the Salem Maritime National Historic Site on March 17, 1938. In 1960, the National Park Service took on the administration of the survey data gathered under this legislation, the National Historic Landmark program began to take more formal shape; when the National Register of Historic Places was established in 1966, the National Historic Landmark program was encompassed within it, rules and procedures for inclusion and designation were formalized. Because listings triggered local preservation laws, legislation in 1980 amended the listing procedures to require owner agreement to the designations. On October 9, 1960, 92 properties were announced as designated NHLs by Secretary of the Interior Fred A. Seaton; the first of these was a political nomination: the Sergeant Floyd Monument in Sioux City, Iowa was designated on June 30 of that year, but for various reasons, the public announcement of the first several NHLs was delayed.
NHLs are designated by the United States Secretary of the Interior because they are: Sites where events of national historical significance occurred. More than 2,500 NHLs have been designated. Most, but not all, are in the United States. There are the District of Columbia. Three states account for nearly 25 percent of the nation's NHLs. Three cities within these states all separately have more NHLs than 40 of the 50 states. In fact, New York City alone has more NHLs than all but five states: Virginia, Pennsylvania and New York. There are 74 NHLs in the District of Columbia; some NHLs are in U. S. commonwealths and territories, associated states, foreign states. There are 15 in Puerto Rico, the Virgin Islands, other U. S. territories. S.-associated states such as Micronesia. Over 100 ships or shipwrecks have been designated as NHLs. About half of the National Historic Landmarks are owned; the National Historic Landmarks Program relies on suggestions for new designations from the National Park Service, which assists in maintaining the landmarks.
A friends' group of owners and managers, the National Historic Landmark Stewards Association, works to preserve and promote National Historic Landmarks. If not listed on the National Register of Historic Places, an NHL is automatically added to the Register upon designation. About three percent of Register listings are NHLs. American Water Landmark List of U. S. National Historic Landmarks by state List of churches that are National Historic Landmarks in the United States Listed building, a similar designation in the UK National Historic Sites and Persons, similar designations in Canada National Natural Landmark United States Memorials United States National Register of Historic Places listings Official National Historic Landmarks Program website A History of the NHL Program List of National Historic Landmarks National Historic Landmarks: Archaeological Properties Historical Landmarks - United States Lighthouses
North American cougar
The North American cougar, is a subspecies of the cougar in North America. It was once found in eastern North America, is still prevalent in the western half of the continent, it is the biggest wild cat in North America. The subspecies P. c. couguar encompasses populations found in the United States, western Canada, the critically endangered Florida panther population, the extinct eastern cougar and Central America, South America northwest of the Andes Mountains. Western populations of the cougar are seen in the former range of the extinct eastern population; the population in Costa Rica had been listed as least concern by the IUCN Red List. Puma concolor costaricensis had been regarded as a subspecies in Central America; as of 2017, P. c. cougar was recognised as being valid by the Cat Classification Taskforce of the Cat Specialist Group. The North American cougar weighs 25 -- 80 kg. Females average 50 kg, about the same as a jaguar in the Chamela-Cuixmala Biosphere Reserve on the Mexican Pacific coast.
The cougar can be found in various habitats. Several populations still exist and are thriving in the Western United States and Western Canada, but the North American cougar was once found in eastern portions of the United States, it was believed to be extirpated there in the early 1900s. Cougars in Michigan were thought to have been extinct in the early 1900s. Today there is evidence to support that cougars could be on the rise in Mexico and could have a substantial population in years to come; some mainstream scientists believe that small relict populations may exist in the Appalachian Mountains and eastern Canada. Recent scientific findings in hair traps in Fundy National Park in New Brunswick have confirmed the existence of at least three cougars in New Brunswick; the Ontario Puma Foundation estimates that there are 850 cougars in Ontario. Reported sightings of cougars in the eastern United States continue today, despite their status as extirpated. WisconsinGenetic analysis of DNA from a cougar sighting in Wisconsin in 2008 indicated that a cougar was in Wisconsin and that it was not a captive animal.
The cougar is thought to have migrated from a native population in the Black Hills of South Dakota. Whether other breeding, cougars are present is uncertain. A second sighting was reported and tracks were documented in a nearby Wisconsin community. A genetic analysis could not be done and a determination could not be made; this cougar made its way south into the northern Chicago suburb of Wilmette. On June 3, 2013, a verified sighting was made in Wisconsin; the cougar was photographed by an automatic trail camera, confirmed by DNR biologists in October, 2013. TennesseeOn September 26, 2015, a hair sample was submitted by a hunter in Carroll County, Tennessee. Bobcats in this state reside in regions that were once roamed by cougars. IllinoisOn April 14, 2008, a cougar triggered a flurry of reports before being cornered and killed in the Chicago neighborhood of Roscoe Village while officers tried to contain it; the cougar was the first sighted in the city limits of Chicago since the city was founded in 1833.
On November 22, 2013, a cougar was found on a farm near Morrison in Illinois. An Illinois Department of Natural Resources officer subsequently shot and killed the cougar after determining it posed a risk to the public. ConnecticutIn 2011, a cougar was sighted in Greenwich and killed by an SUV in Milford after travelling 1,500 mi from South Dakota. While the origins of these animals are unknown, some cougar experts believe some are captive animals that have been released or escaped; this felid hunts at night and may sometimes travel long distances in search of food. Its average litter size is three cubs. Like other cougars, it is fast, can maneuver quite and skillfully. Depending on the abundance of prey such as deer, it may share the same prey as the jaguar in Central or North America. Aside from the jaguar, sympatric predators include American black bears. Cougars are known to prey on bear cubs. Rivalry between the cougar and grizzly was a popular topic in North America. Fights between them were staged, those in the wilderness were recorded by people, including Natives.
Though conservation efforts of the cougar have decreased against the "more appealing" jaguar, it is hunted less because it has no spots, is thus less desirable to hunters. Shasta South American cougar American cheetah Felinae Wright, Bruce S; the Eastern Panther: A Question of Survival. Toronto: Clarke and Company, 1972. Eastern Cougar Foundation National Heritage Information Centre: General Element Report: Puma concolor New York State Department of Environmental Conservation: Eastern Cougar Fact Sheet The IUCN Red List of Threatened Species Photograph of a black or dark cougar in Costa Rica Largest North American Cat: Mountain Lion
Rapid City, South Dakota
Rapid City is the second most populous city in South Dakota and the county seat of Pennington County. Named after Rapid Creek, on which the city is established, it is set against the eastern slope of the Black Hills mountain range; the population was 67,956 as of the 2010 Census. Known as the "Gateway to the Black Hills" due to its location and the "City of Presidents" because of the life-size bronze president statues located downtown. Rapid City is split by a low mountain ridge that divides the eastern parts of the city. Ellsworth Air Force Base is located on the outskirts of the city. Camp Rapid, a part of the South Dakota Army National Guard, is located in the western part of the city. Rapid City is home to popular attractions like Art Alley, Dinosaur Park, the City of Presidents walking tour, Chapel in the Hills, Storybook Island, Main Street Square and more; the historic "Old West" town of Deadwood is nearby. In the neighboring Black Hills are the popular tourist attractions of Mount Rushmore, the Crazy Horse Memorial, Custer State Park, Wind Cave National Park, Jewel Cave National Monument, the museum at the Black Hills Institute of Geological Research, to the east of the city is Badlands National Park.
The public discovery of gold in 1874 by the Black Hills Expedition brought a mass influx of settlers into the Black Hills region of South Dakota. Rapid City was founded, known as "Hay Camp", in 1876 by a group of disappointed miners, who promoted their new city as the "Gateway to the Black Hills", a nickname the city now shares with neighboring Box Elder. John Richard Brennan and Samuel Scott, with a small group of men, laid out the site of the present Rapid City in February 1876, named for the spring-fed Rapid Creek that flows through it. A square mile was measured off and the six blocks in the center were designated as a business section. Committees were appointed to bring in prospective merchants and their families to locate in the new settlement; the city soon began selling supplies to pioneers. Its location on the edge of the Plains and Hills and its large river valley made it the natural hub of railroads arriving in the late 1880s from both the south and east. By 1900, Rapid City had survived a boom and bust and was establishing itself as an important regional trade center for the upper midwest.
Although the Black Hills became a popular tourist destination in the late 1890s, it was a combination of local efforts, the popularity of the automobile, construction of improved highways that brought tourists to the Black Hills in large numbers after World War I. Gutzon Borglum a famous sculptor, began work on Mount Rushmore in 1927 and his son, Lincoln Borglum, continued the carving of the presidents' faces in rock following his father's death in 1941; the work was halted due to pressures leading to the US entry into World War II and the massive sculpture was declared complete in 1941. Although tourism sustained the city throughout the Great Depression of the 1930s, the gasoline rationing of World War II had a devastating effect on the tourist industry in the town, but this was more than made up for by the war-related growth. In 1930, the Rapid City Chamber of Commerce sent a letter inviting Al Capone to live in the Black Hills. South Dakota's governor did not support the idea, neither did Capone, as he declined to relocate to the area.
The city benefited from the opening of Rapid City Army Air Base Ellsworth Air Force Base, an Army Air Corps training base. As a result, the population of the area nearly doubled between 1940 and 1948, from 14,000 to nearly 27,000 people. Military families and civilian personnel soon took every available living space in town, mobile home parks proliferated. Rapid City businesses profited from the military payroll. During the Cold War, missile installations proliferated in the area: a series of Nike Air Defense sites were constructed around Ellsworth in the 1950s. In the early 60s the construction of three Titan missile launch sites containing a total of nine Titan I missiles in the general vicinity of Rapid City took place. Beginning in November 1963, the land for a hundred miles east and northwest of the city was dotted with 150 Minuteman missile silos and 15 launch command centers, all of which were deactivated in the early 1990s. In 1949, city officials envisioned the city as a retail and wholesale trade center for the region and designed a plan for growth that focused on a civic center, more downtown parking places, new schools, paved streets.
A construction boom continued into the 1950s. Growth slowed in the 1960s, but the worst natural disaster in South Dakota history, the Black Hills Flood of 1972, led to another building boom a decade later. On June 9, 1972, heavy rains caused massive flash flooding along the course of Rapid Creek through the city. 238 people lost more than $100 million in property was destroyed. The devastation of the flood and the outpouring of private donations and millions of dollars in federal aid led to the completion of one big part of the 1949 plan: clearing the area along the Rapid Creek and making it a public park. New homes and businesses were constructed to replace those, destroyed. Rushmore Plaza Civic Center and a new Central High School were built in part of the area, cleared; the new Central High School opened in 1978, with the graduating class in that year straddling both the original Central and the new Central. The rebuilding in part insulated Rapid City from the drop in automotive tourism caused by the Oil Embargo in 1974, but tourism was depressed for most of a decade.
In 1978, Rushmore Mall was built on the north edge of the city, adding to the city's position as a retail shoppin
The pronghorn is a species of artiodactyl mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American antelope, prong buck, pronghorn antelope, prairie antelope, or antelope because it resembles the true antelopes of the Old World and fills a similar ecological niche due to parallel evolution, it is the only surviving member of the family Antilocapridae. During the Pleistocene epoch, about 12 antilocaprid species existed in North America. Three other genera existed when humans are now extinct; as a member of the superfamily Giraffoidea, the pronghorn's closest living relatives are the giraffes and okapi. The Giraffoidea are in turn members of the infraorder Pecora, making pronghorns more distant relatives of the Cervidae and Bovidae, among others; the scientific name of the pronghorn is Antilocapra americana. The pronghorn is the sole extant member of the family Antilocapridae; this species was first described by American ornithologist George Ord in 1815.
The pronghorn were first seen and described by Spanish explorers in the 16th century, but were not formally recorded or scrutinised till the 1804–1806 expedition by Captain Meriwether Lewis and Second Lieutenant William Clark. The expedition, which aimed to unravel water routes in the continent for commercial purposes, led to the discovery or formal recognition of a variety of flora and fauna of North America. Following the discovery of a few subspecies of the sharp-tailed grouse and Clark came across the pronghorn near the mouth of the Niobrara River, in present-day Nebraska. Clark was the first to kill a pronghorn, described his experience as follows: I walked on shore to find an old Vulcanoe... in my walk I killed a Buck Goat of this Countrey, about the height of the Grown Deer, its body Shorter the horns, not hard and forks 2⁄3 up one prong Short the other round & Sharp arched, is above its Eyes the Color is a light gray with black behind its ears down the neck, its face white round its neck, its Sides and its rump round its tail, Short & white.
Lewis and Clark made several other observations on the behavior of the pronghorn and how the local tribes hunted them. They described the animal, which they referred to as the "Antelope" or the "Goat", as follows: Of all the animals we have seen the Antelope seems to possess the most wonderful fleetness. Shy and timorous they repose only on the ridges, which command a view of all the approaches of an enemy... When they first see the hunters they run with great velocity... The Indians near the Rocky Mountains hunt these animals on horseback, shoot them with arrows; the Mandans' mode of hunting them is to form a large, strong pen or fold, from which a fence made of bushes widens on each side. The animals are surrounded by the hunters, driven towards this pen, in which they imperceptibly find themselves enclosed, are at the mercy of the hunters. Pronghorns have distinct white fur on their rumps, breasts and across their throats. Adult males are 1.3–1.5 m long from nose to tail, stand 81–104 cm high at the shoulder, weigh 40–65 kg.
The females weigh 34 -- 48 kg. The feet have two hooves, with no dewclaws, their body temperature is 38 °C. The orbits are prominent and set high with never an anteorbital pit, their teeth are hypsodont, their dental formula is 0.0.3.33.1.3.3. Each "horn" of the pronghorn is composed of a slender, laterally flattened blade of bone that grows from the frontal bones of the skull, forming a permanent core; as in the Giraffidae, skin covers the bony cores, but in the pronghorn, it develops into a keratinous sheath, shed and regrown annually. Unlike the horns of the family Bovidae, the horn sheaths of the pronghorn are branched, each sheath having a forward-pointing tine. Males have a horn sheath about 12.5–43 cm long with a prong. Females have smaller horns that range from 2.5–15.2 cm and sometimes visible. Males are further differentiated from females in having a small patch of black hair at the angle of the mandible. Pronghorns have a musky odor. Males mark territory with a preorbital scent gland, on the sides of the head.
They have large eyes with a 320° field of vision. Unlike deer, pronghorns possess a gallbladder; the pronghorn is the fastest land mammal in the Western Hemisphere, being built for maximum predator evasion through running. The top speed is hard to measure and varies between individuals, it is cited as the second-fastest land animal, second only to the cheetah. It can, sustain high speeds longer than cheetahs. University of Idaho zoologist John Byers has suggested the pronghorn evolved its running ability to escape from extinct predators such as the American cheetah, since its speed exceeds that of extant North American predators. Compared to its body size, the pronghorn has a large windpipe and lungs to allow it to take in large amounts of ai
Custer County, South Dakota
Custer County is a county in the U. S. state of South Dakota. As of the 2010 United States Census, the population was 8,216, its county seat is Custer. The county was created in 1875, was organized in 1877. Custer County is included in SD Metropolitan Statistical Area. Custer County lies on the west line of South Dakota, its west boundary line abuts the east boundary line of the state of Wyoming. The Yellowstone River flows northeastward along the upper portion of the county's east boundary. Battle Creek flows southeastward in the upper eastern part of the county, discharging into Yellowstone River along the county's northeastern boundary line. Spring Creek flows northeastward through the upper eastern part of the county, discharging into the river just north of the county border; the county terrain is mountainous its western portion. The terrain slopes to the east, its highest point is a mountain crest along the north boundary line, at 6,657' ASL. Custer County has a total area of 1,559 square miles, of which 1,557 square miles is land and 2.1 square miles is water.
As of the 2000 United States Census, there were 7,275 people, 2,970 households, 2,067 families in the county. The population density was 5 people per square mile. There were 3,624 housing units at an average density of 2 per square mile; the racial makeup of the county was 94.17% White, 0.27% Black or African American, 3.12% Native American, 0.18% Asian, 0.01% Pacific Islander, 0.36% from other races, 1.88% from two or more races. 1.51% of the population were Hispanic or Latino of any race. 32.2 % were of 9.2 % English, 7.1 % Norwegian and 5.7 % American ancestry. There were 2,970 households out of which 26.90% had children under the age of 18 living with them, 60.20% were married couples living together, 6.60% had a female householder with no husband present, 30.40% were non-families. 25.90% of all households were made up of individuals and 10.30% had someone living alone, 65 years of age or older. The average household size was 2.35 and the average family size was 2.80. The county population contained 24.10% under the age of 18, 6.30% from 18 to 24, 22.40% from 25 to 44, 31.10% from 45 to 64, 16.00% who were 65 years of age or older.
The median age was 43 years. For every 100 females there were 104.40 males. For every 100 females age 18 and over, there were 99.40 males. The median income for a household in the county was $36,303, the median income for a family was $43,628. Males had a median income of $30,475 versus $20,781 for females; the per capita income for the county was $17,945. About 6.20% of families and 9.40% of the population were below the poverty line, including 13.00% of those under age 18 and 7.40% of those age 65 or over. As of the 2010 United States Census, there were 8,216 people, 3,636 households, 2,427 families in the county; the population density was 5.3 inhabitants per square mile. There were 4,628 housing units at an average density of 3.0 per square mile. The racial makeup of the county was 94.2% white, 2.9% American Indian, 0.4% Asian, 0.2% black or African American, 0.4% from other races, 2.0% from two or more races. Those of Hispanic or Latino origin made up 2.2% of the population. In terms of ancestry, 42.1% were German, 13.1% were Irish, 11.4% were English, 10.8% were Norwegian, 7.9% were American.
Of the 3,636 households, 21.7% had children under the age of 18 living with them, 58.2% were married couples living together, 5.5% had a female householder with no husband present, 33.3% were non-families, 28.4% of all households were made up of individuals. The average household size was 2.19 and the average family size was 2.65. The median age was 50.3 years. The median income for a household in the county was $46,743 and the median income for a family was $58,253. Males had a median income of $39,194 versus $29,375 for females; the per capita income for the county was $24,353. About 4.3% of families and 9.7% of the population were below the poverty line, including 10.9% of those under age 18 and 11.7% of those age 65 or over. Custer Buffalo Gap Fairburn Hermosa Pringle Dewey Four Mile The county is divided into two areas of territory: East of Custer State Park West of Custer State Park Custer County voters are Republican. In only one national election since 1936 has the county selected the Democratic Party candidate.
National Register of Historic Places listings in Custer County, South Dakota Crazy Horse Memorial
The bighorn sheep is a species of sheep native to North America. The species is aptly named for its large horns. A pair of horns might weigh up to 14 kg. Recent genetic testing indicates three distinct subspecies of Ovis canadensis, one of, endangered: O. c. sierrae. Sheep crossed to North America over the Bering land bridge from Siberia. By 1900, the population had crashed to several thousand, due to diseases introduced through European livestock and overhunting. Ovis canadensis is one of three species of mountain sheep in North Siberia. Wild sheep crossed the Bering land bridge from Siberia into Alaska during the Pleistocene and subsequently spread through western North America as far south as Baja California and northwestern mainland Mexico. Divergence from their closest Asian ancestor occurred about 600,000 years ago. In North America, wild sheep diverged into two extant species—Dall sheep, which occupy Alaska and northwestern Canada, bighorn sheep, which range from southwestern Canada to Mexico.
However, the status of these species is questionable given that hybridization has occurred between them in their recent evolutionary history. In 1940, Ian McTaggart-Cowan split the species into seven subspecies, with the first three being mountain bighorns and the last four being desert bighorns: Rocky Mountain bighorn sheep, O. c. canadensis, found from British Columbia to Arizona. Badlands bighorn sheep or Audubon's bighorn sheep, O. c. auduboni, occurred in North Dakota, South Dakota, Montana and Nebraska. This subspecies has been extinct since 1925. California bighorn sheep, O. c. californiana, found from British Columbia south to California and east to North Dakota. The definition of this subspecies has been updated. Nelson's bighorn sheep, O. c. nelsoni, the most common desert bighorn sheep, ranges from California through Arizona. Mexican bighorn sheep, O. c. mexicana, ranges from Arizona and New Mexico south to Sonora and Chihuahua. Peninsular bighorn sheep O. c. cremnobates, occur in the Peninsular Ranges of California and Baja California Weems' bighorn sheep, O. c. weemsi, found in southern Baja California.
Starting in 1993, Ramey and colleagues, using DNA testing, have shown this division into seven subspecies is illusory. Most scientists recognize three subspecies of bighorn; this taxonomy is supported by the most extensive genetics study to date which found high divergence between Rocky Mountain and Sierra Nevada bighorn sheep, that these two subspecies both diverged from desert bighorn prior to or during the Illinoian glaciation. Thus, the three subspecies of O. canadensis are: Rocky Mountain bighorn sheep – occupying the U. S. and Canadian Rocky Mountains, the Northwestern United States. Sierra Nevada bighorn sheep – California bighorn sheep, a genetically distinct subspecies that only occurs in the Sierra Nevada in California. However, historic observer records suggest that bighorn sheep may have ranged as far west as the California Coastal Ranges which are contiguous to the Sierra Nevada via the Transverse Ranges. An account of "wild sheep" in the vicinity of the Mission San Antonio near Jolon and the mountains around San Francisco Bay dates to circa 1769.
Desert bighorn sheep – occurring throughout the desert regions of the Southwestern United States and Northwestern Mexico. The 2016 genetics study suggested more modest divergence of this desert bighorn sheep into three lineages consistent with the earlier work of Cowan: Nelson's, Peninsular; these three lineages occupy desert biomes that vary in climate, suggesting exposure to different selection regimens. In addition, two populations are considered endangered by the United States government: Sierra Nevada bighorn sheep, Peninsular bighorn sheep, a distinct population segment of desert bighorn sheep Bighorn sheep are named for the large, curved horns borne by the rams. Ewes have horns, but they are shorter with less curvature, they range in color from light brown to grayish or dark, chocolate brown, with a white rump and lining on the backs of all four legs. Males weigh 58–143 kg, are 90–105 cm tall at the shoulder, 1.6–1.85 m long from the nose to the tail. Females are 34–91 kg, 75–90 cm tall, 1.28–1.58 m long.
Male bighorn sheep have large horn cores, enlarged cornual and frontal sinuses, internal bony septa. These adaptations serve to protect the brain by absorbing the impact of clashes. Bighorn sheep have preorbital glands on the anterior corner of each eye, inguinal glands in the groin, pedal glands on each foot. Secretions from these glands may support dominance behaviors. Bighorns from the Rocky Mountains are large, with males that exceed 230 kg and females that exceed 90 kg. In contrast, Sierra Nevada bighorn males weigh up to females to 60 kg. Males' horns can weigh up to 14 kg, as much as the rest of the bones in the male's body; the Rocky Mountains and Sierra Nevada bighorn sheep occupy the cooler mountainous regions of Canada and the United States. In contrast, the desert bighorn sheep subspecies are indigeno