The Sonoran Desert is a North American desert which covers large parts of the Southwestern United States in Arizona and California and of Northwestern Mexico in Sonora, Baja California, Baja California Sur. It is the hottest desert in Mexico, it has an area of 260,000 square kilometers. The western portion of the United States–Mexico border passes through the Sonoran Desert. In phytogeography, the Sonoran Desert is within the Sonoran Floristic Province of the Madrean Region in southwestern North America, part of the Holarctic Kingdom of the northern Western Hemisphere; the desert contains a variety of unique and endemic plants and animals, such as the saguaro and organ pipe cactus. The Sonoran desert wraps around the northern end of the Gulf of California, from Baja California Sur, north through much of Baja California, excluding the central northwest mountains and Pacific west coast, through southeastern California and southwestern and southern Arizona to western and central parts of Sonora.
It is bounded on the west by the Peninsular Ranges, which separate it from the California chaparral and woodlands and Baja California Desert ecoregions of the Pacific slope. To the north in California and northwest Arizona, the Sonoran Desert transitions to the colder-winter, higher-elevation Mojave, Great Basin, Colorado Plateau deserts. To the east and southeast, the deserts transition to the coniferous Arizona Mountains forests and Sierra Madre and Sierra Madre Occidental pine–oak forests at higher elevations. To the south the Sonoran–Sinaloan transition subtropical dry forest is the transition zone from the Sonoran Desert to the tropical dry forests of the Mexican state of Sinaloa; the desert's sub-regions include the Colorado Desert of southeastern California. In the 1957 publication Vegetation of the Sonoran Desert, Forrest Shreve divided the Sonoran Desert into seven regions according to characteristic vegetation: Lower Colorado Valley, Arizona Upland, Plains of Sonora, Foothills of Sonora, Central Gulf Coast, Vizcaíno Region, Magdalena Region.
Many ecologists now consider Shreve's Vizcaíno and Magdalena regions, which lie on the western side of the Baja California Peninsula, to be a separate ecoregion, the Baja California Desert. Within the southern Sonoran Desert in Mexico is found the Gran Desierto de Altar, with the Reserva de la Biosfera el Pinacate y Gran Desierto de Altar, extending 2,000 square kilometers of desert and mountainous regions; the Pinacate National Park includes the only active erg dune region in North America. The nearest city to the Reserva de la Biosfera el Pinacate y Gran Desierto de Altar is Puerto Peñasco in the state of Sonora, Mexico. Sub-regionsSonoran Desert sub-regions include: Colorado Desert Gran Desierto de Altar Lechuguilla Desert Tonopah Desert Yuha Desert Yuma Desert The Sonoran Desert includes 60 mammal species, 350 bird species, 20 amphibian species, over 100 reptile species, 30 native fish species, over 1000 native bee species, more than 2,000 native plant species; the Sonoran Desert area southeast of Tucson and near the Mexican border is vital habitat for the only population of jaguars living within the United States.
The Colorado River Delta was once an ecological hotspot within the Sonoran desert, fueled by the flow of fresh water through the Colorado river in this otherwise dry area, but the delta has been reduced in extent due to the damming and use of the river upstream. Many plants not only thrive in the harsh conditions of the Sonoran Desert. Many have evolved to have specialized adaptations to the desert climate; the Sonoran Desert's biseasonal rainfall pattern results in more plant species than any other desert in the world. The Sonoran Desert includes plant genera and species from the agave family, palm family, cactus family, legume family, numerous others; the Sonoran is the only place in the world. Cholla, hedgehog, prickly pear, nightblooming cereus, organ pipe are other taxa of cacti found here. Cactus provides food and homes to many desert mammals and birds, with showy flowers in reds, pinks and whites, blooming most from late March through June, depending on the species and seasonal temperatures.
Creosote bush and bur sage dominate valley floors. Indigo bush and Mormon tea are other shrubs. Wildflowers of the Sonoran Desert include desert sand verbena, desert sunflower, evening primroses. Ascending from the valley up bajadas, various subtrees such as velvet mesquite, palo verde, desert ironwood, desert willow, crucifixion thorn are common, as well as multi-stemmed ocotillo. Shrubs found at higher elevations include whitethorn acacia, fairy duster, jojoba. In the desert subdivisions found on Baja California, cardon cactus, elephant tree, boojum tree occur; the California fan palm is found in the Colorado Desert section of the Sonoran Desert, the only native palm in California, among many other introduced Arecac
Arizona is a state in the southwestern region of the United States. It is part of the Western and the Mountain states, it is the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona shares the Four Corners region with Utah and New Mexico. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912, coinciding with Valentine's Day. Part of the territory of Alta California in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848; the southernmost portion of the state was acquired in 1853 through the Gadsden Purchase. Southern Arizona is known for its desert climate, with hot summers and mild winters. Northern Arizona features forests of pine, Douglas fir, spruce trees. There are ski resorts in the areas of Flagstaff and Tucson. In addition to the Grand Canyon National Park, there are several national forests, national parks, national monuments.
About one-quarter of the state is made up of Indian reservations that serve as the home of 27 federally recognized Native American tribes, including the Navajo Nation, the largest in the state and the United States, with more than 300,000 citizens. Although federal law gave all Native Americans the right to vote in 1924, Arizona excluded those living on reservations in the state from voting until the state Supreme Court ruled in favor of Native American plaintiffs in Trujillo v. Garley; the state's name appears to originate from an earlier Spanish name, derived from the O'odham name alĭ ṣonak, meaning "small spring", which applied only to an area near the silver mining camp of Planchas de Plata, Sonora. To the European settlers, their pronunciation sounded like "Arissona"; the area is still known as alĭ ṣonak in the O'odham language. Another possible origin is the Basque phrase haritz ona, as there were numerous Basque sheepherders in the area. A native Mexican of Basque heritage established the ranchería of Arizona between 1734 and 1736 in the current Mexican state of Sonora, which became notable after a significant discovery of silver there, c.
1737. There is a misconception. For thousands of years before the modern era, Arizona was home to numerous Native American tribes. Hohokam and Ancestral Puebloan cultures were among the many that flourished throughout the state. Many of their pueblos, cliffside dwellings, rock paintings and other prehistoric treasures have survived, attracting thousands of tourists each year; the first European contact by native peoples was with Marcos de Niza, a Spanish Franciscan, in 1539. He explored parts of the present state and made contact with native inhabitants the Sobaipuri; the expedition of Spanish explorer Coronado entered the area in 1540–1542 during its search for Cíbola. Few Spanish settlers migrated to Arizona. One of the first settlers in Arizona was José Romo de Vivar. Father Kino was the next European in the region. A member of the Society of Jesus, he led the development of a chain of missions in the region, he converted many of the Indians to Christianity in the Pimería Alta in the 1690s and early 18th century.
Spain founded presidios at Tubac in 1752 and Tucson in 1775. When Mexico achieved its independence from the Kingdom of Spain and its Spanish Empire in 1821, what is now Arizona became part of its Territory of Nueva California known as Alta California. Descendants of ethnic Spanish and mestizo settlers from the colonial years still lived in the area at the time of the arrival of European-American migrants from the United States. During the Mexican–American War, the U. S. Army occupied the national capital of Mexico City and pursued its claim to much of northern Mexico, including what became Arizona Territory in 1863 and the State of Arizona in 1912; the Treaty of Guadalupe Hidalgo specified that, in addition to language and cultural rights of the existing inhabitants of former Mexican citizens being considered as inviolable, the sum of US$15 million dollars in compensation be paid to the Republic of Mexico. In 1853, the U. S. acquired the land south below the Gila River from Mexico in the Gadsden Purchase along the southern border area as encompassing the best future southern route for a transcontinental railway.
What is now known as the state of Arizona was administered by the United States government as part of the Territory of New Mexico until the southern part of that region seceded from the Union to form the Territory of Arizona. This newly established territory was formally organized by the Confederate States government on Saturday, January 18, 1862, when President Jefferson Davis approved and signed An Act to Organize the Territory of Arizona, marking the first official use of the name "Territory of Arizona"; the Southern territory supplied the Confederate government with men and equipment. Formed in 1862, Arizona scout companies served with the Confederate States Army duri
Interstate 70 is a major east–west Interstate Highway in the United States that runs from I-15 near Cove Fort, Utah, to I-695 near Baltimore, Maryland. I-70 traces the path of U. S. Route 40 east of the Rocky Mountains. West of the Rockies, the route of I-70 was derived from multiple sources; the Interstate runs through or near many major cities, including Denver, Kansas City, St. Louis, Columbus and Baltimore; the sections of the interstate in Missouri and Kansas have laid claim to be the first interstate in the United States. The Federal Highway Administration has claimed the section of I-70 through Glenwood Canyon, completed in 1992, was the last piece of the Interstate Highway system, as planned, to open to traffic; the construction of I-70 in Colorado and Utah is considered an engineering marvel, as the route passes through the Eisenhower Tunnel, Glenwood Canyon, the San Rafael Swell. The Eisenhower Tunnel is the highest point along the Interstate Highway system, with an elevation of 11,158 ft. Interstate 70 begins at an interchange with Interstate 15 near Cove Fort.
Heading east, I-70 crosses between the Tushar and Pahvant ranges via Clear Creek Canyon and descends into the Sevier Valley, where I-70 serves Richfield, the only town of more than a few hundred people along I-70's path in Utah. Upon leaving the valley near Salina, I-70 crosses the 7,923 ft Salina Summit and crosses a massive geologic formation called the San Rafael Swell. Prior to the construction of I-70, the swell was inaccessible via paved roads and undiscovered. Once this 108 mi section was opened to traffic in 1970, it became the longest stretch of interstate highway with no services and the first highway in the U. S. built over a new route since the Alaska Highway. It became the longest piece of interstate highway to be opened at one time. Although opened in 1970, this section was not formally complete until 1990, when a second steel arch bridge spanning Eagle Canyon was opened to traffic. Since I-70's construction, the swell has been noted for its desolate beauty; the swell has since been nominated for National Park or National Monument status on multiple occasions.
If the swell is granted this status, it arguably would be the first time a National Park owes its existence to an interstate highway. Most of the exits in this span are rest areas, brake check areas, runaway truck ramps with few traditional freeway exits. I-70 exits the swell near Green River. From Green River to the Colorado state line, I-70 follows the southern edge of the Book Cliffs. Entering from Utah, I-70 descends into the Grand Valley, where it meets the Colorado River, which provides its path up the western slope of the Rocky Mountains. Here I-70 serves the Grand Junction metro area before traversing more mountainous terrain; the last section of I-70 to be completed was the 15-mile Glenwood Canyon. This stretch was completed in 1992 and was an engineering marvel, due to the difficult terrain and narrow space in the canyon, which requires corners that are sharper than normal Interstate standards. Construction was delayed for many years due to environmental concerns; the difficulties in building the road in the canyon were compounded by the fact the Denver & Rio Grande Western railroad occupied the south bank, many temporary construction projects took place to keep US 6 open, at the time the only east–west road in the area.
Much of the highway is elevated above the Colorado River. The speed limit in this section is due to the limited sight distance and sharp corners; the Eisenhower–Johnson Memorial Tunnel, the highest vehicular tunnel in North America and the longest tunnel built under the Interstate program, passes through the Continental Divide. Because of the rugged and narrow terrain of the Rocky Mountains, I-70 is one of few roads connecting Colorado's ski resorts with Denver. Descending through the eastern foothills of the Rocky Mountains, one can see the Denver skyline on a clear day; this can fool truckers and other unsuspecting drivers, because one must still traverse 10 miles of steep grade road before reaching the city. A series of signs warns truckers of the steep grade; as I-70 leaves the foothills, it goes through Denver and intersects Interstate 25, serving as the central east-west artery through the city. Leaving Denver, I-70 levels out and traverses the wide plains through eastern Colorado. East of Denver, I-70 makes a broad turn to the south-southeast for 30 miles before reaching Limon and resuming its eastward journey toward Kansas.
Coming from Colorado, I-70 enters the prairie and rolling hills of Kansas. This portion of I-70 was the first segment to start being paved and to be completed in the Interstate Highway System, it is given the nickname "Main Street of Kansas", as the interstate extends from the western border to the eastern border of the state, covering 424 miles and passing through most of the state's principal cities in the process. In Salina, I-70 intersects with I-135, the longest "spur" route in the Interstate system, forming the latter's northern terminus. In Topeka, I-70 intersects I-470, twice. At the eastern intersection, the Kansas Turnpike merges, with I-70 becoming a toll road; this is one of only two sections of I-70. I-70 carries this designation from Topeka to the eastern terminus of the turnpike. About halfway between Topeka and Kansas City, Kansas, I-70 passes through Lawrence; the tolled portion of the turnpike ends near Bonner Springs, just west of Kansas City. There is a third child route in Topeka, I-335, which runs from I-470 south to meet up wit
The Salton Sea is a shallow, endorheic rift lake located directly on the San Andreas Fault, predominantly in the U. S. state of California's Imperial and Coachella valleys. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Imperial and Riverside counties in Southern California, its surface is 236.0 ft below sea level as of January 2018. The deepest point of the sea is 5 ft higher than the lowest point of Death Valley; the sea is fed by the New and Alamo Rivers, as well as agricultural runoff, drainage systems, creeks. Over millions of years, the Colorado River has flowed into the Imperial Valley and deposited soil, building up the terrain and changing the course of the river. For thousands of years, the river has alternately flowed into and out of the valley, alternately creating a freshwater lake, an saline lake, a dry desert basin, depending on river flows and the balance between inflow and evaporative loss; the cycle of filling has repeated many times. The latest natural cycle occurred around 1600–1700 as remembered by Native Americans who talked with the first European settlers.
Fish traps still exist at many locations, the Native Americans evidently moved the traps depending upon the cycle. The most recent inflow of water from the now controlled Colorado River was accidentally created by the engineers of the California Development Company in 1905. In an effort to increase water flow into the area for farming, irrigation canals were dug from the Colorado River into the valley; the canals suffered silt buildup, so a cut was made in the bank of the Colorado River to further increase the water flow. The resulting outflow overwhelmed the engineered canal near Yuma and the river flowed into the Salton Basin for two years, filling the historic dry lake bed and creating the modern sea, before repairs were completed. While it varies in dimensions and area with fluctuations in agricultural runoff and rainfall, the Salton Sea is about 15 by 35 miles. With an estimated surface area of 343 square miles or 350 square miles, the Salton Sea is the largest lake in California; the average annual inflow is less than 1.2 million acre⋅ft, enough to maintain a maximum depth of 43 feet and a total volume of about 6 million acre⋅ft.
However, due to changes in water apportionments agreed upon for the Colorado River under the Quantification Settlement Agreement of 2003, the overall water level of the sea is expected to decrease between 2013 and 2021. The lake's salinity, about 56 grams per litre, is greater than that of the Pacific Ocean, but less than that of the Great Salt Lake; the concentration has been increasing at a rate of about 3% per year. About 4 million short tons of salt are deposited in the valley each year; the area was once part of a vast inland sea. Geologists estimate that for three million years, at least through all the years of the Pleistocene glacial age, a large delta was deposited by the Colorado River in the southern region of the Imperial Valley; the delta reached the western shore of the Gulf of California, creating a barrier that separated the area of the Salton Sea from the northern reaches of the Gulf. Were it not for this barrier, the entire Salton Sink along with the Imperial Valley would be submerged as the Gulf would extend as far north as Indio.
Since the exclusion of the ocean, the Salton Basin has over the ages been alternately a freshwater lake, an saline endorheic lake, a dry desert basin, depending on river flows and the balance between inflow and evaporative loss. A lake exists only during times it is replenished by the rivers and rainfall, a cycle that has repeated many times over hundreds of thousands of years cycling every 400 to 500 years. Evidence that the basin was occupied periodically by multiple lakes includes wave-cut shorelines at various elevations preserved on the hillsides of the east and west margins of the present lake, the Salton Sea; these indicate that the basin was occupied intermittently as as a few hundred years ago. The last of the Pleistocene lakes to occupy the basin was Lake Cahuilla periodically identified on older maps as Lake LeConte or the Blake Sea, after American professor and geologist William Phipps Blake. Throughout the Spanish period of California's history, the area was referred to as the "Colorado Desert" after the Colorado River.
In a railroad survey completed in 1855, it was called "the Valley of the Ancient Lake". On several old maps from the Library of Congress, it has been found labeled "Cahuilla Valley" and "Cabazon Valley". "Salt Creek" first appeared on a map in 1867 and "Salton Station" is on a railroad map from 1900, although this place had been there as a rail stop since the late 1870s. Until the advent of the modern sea, the Salton Sink was the site of a major salt-mining operation. In 1900, the California Development Company began construction of irrigation canals to divert water from the Colorado River into the Salton Sink, a dry lake bed. After construction of these irrigation canals, the Salton Sink became fertile for a time, allowing farmers to plant crops. Within two years, the Imperial Canal became filled with silt from the Colorado River. Engineers tried to alleviate the blockages to no avail. In 1905, heavy rainfall and snowmelt caused the Colorado River to swell, overrunning a set of headgates for the Alamo Canal.
Cataract Canyon is a 46-mile-long canyon of the Colorado River located within Canyonlands National Park and Glen Canyon National Recreation Area in southern Utah. It begins at the Colorado's confluence with the Green River and its downstream terminus is the confluence with the Dirty Devil River; the lower half of the canyon is submerged beneath Lake Powell when the lake is at its normal high water elevation of 3,700 feet. Cataract Canyon is cut by the Colorado River into the Colorado Plateau, a vast continental uplift comprising much of the American Southwest; until 80 million years ago, the Colorado Plateau was near sea level. Over millions of years, a series of inland oceans transgressed onto and regressed from the region, resulting in a series of horizontally deposited rock layers. 70 to 80 million years ago, a series of mountain-building events called the Laramide orogeny uplifted the entire region. The Colorado River subsequently cut through the rock layers; the oldest rock layer visible in Cataract Canyon is the Paradox Formation, deposited 320 million years ago.
Indigenous peoples, most of the Fremont culture, inhabited the Canyonlands area long before European settlers arrived. Rock art and ruins have been found in Cataract Canyon; because of the remote location, it was some time before European explorers and settlers reached the area. The Colorado River and its canyons were more of an obstacle to travel than a destination to be explored; the first recorded European to reach Cataract Canyon was a fur trapper named Denis Julien in 1836. Julien carved his name into a rock wall in the lower section of Cataract Canyon, though this inscription is now covered by Lake Powell; the first organized exploration to travel the entire length of Cataract Canyon was the Powell Expedition in 1869, led by John Wesley Powell, a one-armed Civil War veteran who launched in wooden boats near Green River and traveled down the Green River to its confluence with the Colorado River at the top of Cataract Canyon. The rapids of Cataract Canyon terrified Powell and his men; the expedition portaged their boats around every rapid in a difficult and arduous task.
Because of the difficulty of the rapids, Powell named the canyon Cataract Canyon. After exiting Cataract Canyon, Powell continued his trip downstream through Glen Canyon, now submerged by Lake Powell, the Grand Canyon before ending his trip near the mouth of the Virgin River. Other river runners soon followed. Nathanial Galloway made numerous trips through the canyon beginning in 1894. Galloway would go on to pioneer rowing techniques still used by river runners today. Brothers Emery and Ellsworth Kolb traveled through the canyon in 1911; the Kolb brothers established a studio on the south rim of the Grand Canyon where they featured videos of their exploits running the rapids of the Colorado River. Buzz Holmstrom made a solo trip through Cataract Canyon and Grand Canyon in 1937 ending at the newly constructed Hoover Dam; the first commercial outfitter to offer trips through Cataract Canyon was Norman Nevills in 1938. The advent of rubber rafts came about in the early 1950s with the availability of surplus rubber rafts from World War II.
River runners found the rubber rafts easier to maneuver and much more forgiving than their wooden counterparts. With this newer equipment, many commercial outfitters began running Grand Canyon and Cataract Canyon. Cataract Canyon remains a popular whitewater rafting destination today; the rapids in the canyon are considered "big water", with a character similar to those found in Grand Canyon. Cataract Canyon is rated on the Class I-VI International Scale of River Difficulty, unlike the Grand Canyon, rated on a scale of one to ten. Unlike Grand Canyon, the flow of the Colorado River through Cataract Canyon is far enough downstream from a dam that it is unregulated; the river can reach extreme levels during the spring runoff in years following plentiful snow throughout the Colorado River watershed. During an average spring runoff, the Colorado River will peak at 52,000 cu ft/s; the maximum recorded flow of 114,900 cu ft/s occurred on May 27, 1984. The rapids of Cataract Canyon become difficult at flows above 30,000 cu ft/s and extreme at flows above 50,000 cu ft/s.
Most rapids in Cataract Canyon are named from upstream to downstream as Rapid 1, Rapid 2, etc. However, some rapids within the canyon have separate names due to their notoriety. Notorious are the "Big Drops", a set of three rapids in short succession named "Big Drop 1", "Big Drop 2" and "Big Drop 3". During high water, these three rapids run together to form one large rapid; these rapids contain many large hydraulic features including "Little Niagara", "Satan's Gut", "The Claw". During times of high runoff, the National Park Service sometimes establishes a camp below the big drops and uses a jetboat to facilitate rescues of capsized rafts and their passengers. However, it is understood that all river runners attempting Cataract Canyon at any river level should be capable of self-rescue and not depend on the NPS for support. Cataract Canyon contained several rapids which are submerged beneath Lake Powell and have been buried in lake sediment. "Gypsum Canyon Rapid" and "Dark Canyon Rapid" in particular were considered difficult rapids to navigate.
River trips which run Cataract Canyon must run one of the flatwater sections above the confluence of the Green and Colorado Rivers. Most groups launch at Potash or Mineral Bottom and spend up to five days
The Parker Valley is located along the Lower Colorado River within the Lower Colorado River Valley region, in southwestern Arizona and southeastern California. Its natural habitats are within the Sonoran Colorado Desert ecoregions. Riparian zone habitats on the river include Mesquite Bosques; the river has supported irrigated agricultural conversion of the valley's landscape. Three major drainages of the Colorado River enter in the Parker Valley region; the Bill Williams River and Bouse Wash have confluences with the Colorado in the northern valley area, from watersheds on the east. Tyson Wash crosses the La Posa Plain and enters downstream, with its watershed east of the river in the Colorado River Indian Reservation. In California, the Vidal Valley and the Whipple Mountains border the Parker Valley on the northwest, the Palo Verde Valley on the southwest. In Arizona the Buckskin Mountains border the valley on the north, the Cactus Plain and Dome Rock Mountains border it on the east. Settlements within Parker Valley include: Parker and Poston in Arizona.
It is at the northern area of the Colorado River Indian Reservation on the Colorado River, is at the northern perimeter of the La Posa Plain. Valleys of the Lower Colorado River Valley U. S. Geological Survey Geographic Names Information System: Parker Valley Arizona Atlas & Gazetteer, DeLorme, c. 2002, p. 70