Saguaro National Park

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Saguaro National Park
IUCN category II (national park)
Saguaro Sunset.jpg
Sunset in the Rincon Mountain District of the park
Arizona Locator Map with Lower-Left Inset.png
Red pog.svg
Location of Saguaro National Park in Arizona.
Inset: Arizona in the United States.
Location Tucson, Arizona, Pima, Arizona, United States
Coordinates 32°10′45″N110°44′13″W / 32.17917°N 110.73694°W / 32.17917; -110.73694 Coordinates: 32°10′45″N110°44′13″W / 32.17917°N 110.73694°W / 32.17917; -110.73694
Area91,716 acres (371.16 km2) [1]
EstablishedOctober 14, 1994 [2]
Named for Saguaro, a cactus
Visitors957,405(in 2018) [3]
Governing bodyNational Park Service
Website Official website Blue pencil.svg

Saguaro National Park is an American national park in Pima County, southeastern Arizona. The 92,000-acre (37,000 ha) park consists of two separate areas—the Tucson Mountain District (TMD) about 10 miles (16 km) west of the city of Tucson and the Rincon Mountain District (RMD) about 10 miles (16 km) east of the city—that preserve Sonoran Desert landscapes, fauna, and flora, including the giant saguaro cactus.

National park park used for conservation purposes of animal life and plants

A national park is a park in use for conservation purposes. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently, there is a common idea: the conservation of 'wild nature' for posterity and as a symbol of national pride. An international organization, the International Union for Conservation of Nature (IUCN), and its World Commission on Protected Areas (WCPA), has defined "National Park" as its Category II type of protected areas.

Pima County, Arizona County in the United States

Pima County is a county in the south central region of the U.S. state of Arizona. As of the 2010 census, the population was 980,263, making it Arizona's second-most populous county. The county seat is Tucson, where nearly all of the population is centered. The county is named after the Pima Native Americans who are indigenous to this area.

Arizona state of the United States of America

Arizona is a state in the southwestern region of the United States. It is also part of the Western and the Mountain states. It is the sixth largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona shares the Four Corners region with Utah, Colorado, and New Mexico; its other neighboring states are Nevada and California to the west and the Mexican states of Sonora and Baja California to the south and southwest.

Contents

The volcanic rocks on the surface of the Tucson Mountain District differ greatly from the surface rocks of the Rincon Mountain District; over the past 30 million years, crustal stretching displaced rocks from beneath the Tucson Mountains of the Tucson Mountain District to form the Rincon Mountains of the Rincon Mountain District. Uplifted, domed, and eroded, the Rincon Mountains are significantly higher and wetter than the Tucson Mountains. The Rincons, as one of the Madrean Sky Islands between the southern Rocky Mountains and the Sierra Madre Oriental in Mexico, support high biodiversity and are home to many plants and animals that do not live in the Tucson Mountain District.

Tucson Mountains

The Tucson Mountains are a minor mountain range west of Tucson, Arizona. The Tucson Mountains, including Wasson Peak, are one of four notable mountain ranges surrounding the Tucson Basin. The Santa Catalina Mountains lie to the northeast, the Rincon Mountains are to the east of Tucson, and the Santa Rita Mountains lie to the south. Additionally the Sierrita Mountains lie due south, the Roskruge Mountains lie to the west across Avra Valley, the Silver Bell Mountains lie to the northwest, and the Tortolita Mountains lie to the north across the Santa Cruz Valley.

Rincon Mountains

The Rincon Mountains are a significant mountain range east of Tucson, Pima County, Arizona, in the United States. The Rincon Mountains are one of five mountain ranges surrounding the Tucson valley. The other ranges include the most prominent, the Santa Catalina Mountains to the north, the Santa Rita Mountains to the south, the Tucson Mountains to the west, and the Tortolita Mountains to the northwest. Redington Pass separates the Rincon Mountains from the Santa Catalina Mountains. The Rincon Mountains are generally less rugged than the Santa Catalina Mountains and Santa Rita Mountains. The Rincon Mountains are also included in the Madrean sky island mountain ranges of southeast Arizona, extreme southwest New Mexico, and northern Sonora Mexico.

Madrean Sky Islands

The Madrean Sky Islands are enclaves of Madrean pine-oak woodlands, found at higher elevations in a complex of small mountain ranges in southern and southeastern Arizona, southwestern New Mexico, and northwestern Mexico. The sky islands are surrounded at lower elevations by the Sonoran and Chihuahuan deserts. The northern west–east perimeter of the sky island region merges into the higher elevation eastern Mogollon Rim and the White Mountains of eastern Arizona.

Earlier residents of and visitors to the lands in and around the park before its creation included the Hohokam, Sobaipuri, Tohono O'odham, Apaches, Spanish explorers, missionaries, miners, homesteaders, and ranchers. In 1933, President Herbert Hoover, using the power of the Antiquities Act, established the original park, Saguaro National Monument, in the Rincon Mountains. In 1961, President John F. Kennedy added the Tucson Mountain District to the monument and renamed the original tract the Rincon Mountain District. Congress combined the Tucson Mountain District and the Rincon Mountain District to form the national park in 1994.

Hohokam ethnic group

The Hohokam were an ancient Native American culture centered in the present US state of Arizona. The Hohokam are one of the four major cultures of the American Southwest and northern Mexico in Southwestern archaeology. Considered part of the Oasisamerica tradition, the Hohokam established significant trading centers such as at Snaketown, and are considered to be the builders of the original canal system around the Phoenix metropolitan area, which the Mormon pioneers rebuilt when they settled the Lehi area of Mesa near Red Mountain. Variant spellings in current, official usage include Hobokam, Huhugam, and Huhukam.

The Sobaipuri were one of many indigenous groups occupying Sonora and what is now Arizona at the time Europeans first entered the American Southwest. They were a Piman or O'odham group who occupied southern Arizona and northern Sonora in the 15th-19th centuries. They were a subgroup of the O'odham or Pima, surviving members of which include the residents of San Xavier del Bac which is now part of the Tohono O'odham Nation and the Akimel O'odham.

The Apache are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Salinero, Plains and Western Apache. Distant cousins of the Apache are the Navajo, with which they share the Southern Athabaskan languages. There are Apache communities in Oklahoma, Texas, and reservations in Arizona and New Mexico. Apache people have moved throughout the United States and elsewhere, including urban centers. The Apache Nations are politically autonomous, speak several different languages and have distinct cultures.

Popular activities in the park include hiking on its 165 miles (266 km) of trails and sightseeing along paved roads near its two visitor centers. Both districts allow bicycling and horseback riding on selected roads and trails. The Rincon Mountain District offers limited wilderness camping, but there is no overnight camping in the Tucson Mountain District.

Names

The park gets its name from the saguaro (Carnegiea gigantea), [4] a large cactus that is native to the Sonoran Desert and that does not grow naturally elsewhere. [5] Rincón—as in Rincon Mountains, Rincon Creek, and Rincon Valley—is Spanish for corner, [6] and refers to the shape of the mountain range and its footprint. [7] The name Tucson derives from Papago-Piman words cuk ṣon [ˡtʃukʂɔn], meaning dark spring or brown spring. [8] Tank or Tanque refers to a small artificial pool behind a dam that traps runoff in an existing natural depression. [9] Madrean derives from Madre in Sierra Madre [10] (Mother Mountains [11] ).

Saguaro species of plant

The saguaro is an arborescent (tree-like) cactus species in the monotypic genus Carnegiea, which can grow to be over 40 feet (12 m) tall. It is native to the Sonoran Desert in Arizona, the Mexican State of Sonora, and the Whipple Mountains and Imperial County areas of California. The saguaro blossom is the state wildflower of Arizona. Its scientific name is given in honor of Andrew Carnegie. In 1994, Saguaro National Park, near Tucson, Arizona, was designated to help protect this species and its habitat.

Cactus family of mostly succulent plants, adapted to dry environments

A cactus is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word "cactus" derives, through Latin, from the Ancient Greek κάκτος, kaktos, a name originally used by Theophrastus for a spiny plant whose identity is not certain. Cacti occur in a wide range of shapes and sizes. Most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on earth. Cacti show many adaptations to conserve water. Almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka.

Spanish language Romance language

Spanish or Castilian, is a Western Romance language that originated in the Castile region of Spain and today has hundreds of millions of native speakers in the Americas and Spain. It is a global language and the world's second-most spoken native language, after Mandarin Chinese.

Geography and climate

The park consists of two separate parcels, the Tucson Mountain District (TMD) to the west of Tucson, Arizona, and the Rincon Mountain District (RMD) to the east. Each parcel comes within about 10 miles (16 km) of the center of the city. [12] Their total combined area in 2016 was 91,716 acres (37,116 ha). [1] The Tucson Mountain District covers about 25,000 acres (10,000 ha), [13] while the much larger Rincon Mountain District accounts for the balance of about 67,000 acres (27,000 ha). [14] About 71,000 acres (29,000 ha) of the park, including large fractions of both districts, is designated wilderness. [15]

Tucson, Arizona City in Arizona, United States

Tucson is a city and the county seat of Pima County, Arizona, United States, and home to the University of Arizona. The 2010 United States Census put the population at 520,116, while the 2015 estimated population of the entire Tucson metropolitan statistical area (MSA) was 980,263. The Tucson MSA forms part of the larger Tucson-Nogales combined statistical area (CSA), with a total population of 1,010,025 as of the 2010 Census. Tucson is the second-largest populated city in Arizona behind Phoenix, both of which anchor the Arizona Sun Corridor. The city is 108 miles (174 km) southeast of Phoenix and 60 mi (97 km) north of the U.S.–Mexico border. Tucson is the 33rd largest city and the 58th largest metropolitan area in the United States (2014).

National Wilderness Preservation System

The National Wilderness Preservation System (NWPS) of the United States protects federally managed wilderness areas designated for preservation in their natural condition. Activity on formally designated wilderness areas is coordinated by the National Wilderness Preservation System. Wilderness areas are managed by four federal land management agencies: the National Park Service, the U.S. Forest Service, the U.S. Fish and Wildlife Service, and the Bureau of Land Management. The term "wilderness" is defined as "an area where the earth and community of life are untrammeled by man, where man himself is a visitor who does not remain" and "an area of undeveloped Federal land retaining its primeval character and influence, without permanent improvements or human habitation, which is protected and managed so as to preserve its natural conditions." As of 2016, there are 765 designated wilderness areas, totaling 109,129,657 acres (44,163,205 ha), or about 4.5% of the area of the United States.

Interstate 10, the major highway nearest to the park, passes through Tucson. [16] Tucson Mountain Park abuts the south side of the Tucson Mountain District, and to its west lies the Avra Valley. [16] The Rincon Mountain Wilderness, a separate protected area of about 37,000 acres (15,000 ha) [17] in the Coronado National Forest, [18] abuts the Rincon Mountain District on the east and southeast, while the Rincon Valley lies immediately south of the western part of the Rincon Mountain District. [16]

In the U.S. state of Arizona, Interstate 10 (I‑10), the major east–west Interstate Highway in the United States Sun Belt, runs east from California, enters Arizona near the town of Ehrenberg and continues through Phoenix and Tucson and exits at the border with New Mexico near San Simon. The highway also runs through the cities of Casa Grande, Eloy, and Marana. Segments of the highway are referred to as either the Papago Freeway, Inner Loop, or Maricopa Freeway within the Phoenix area, and the Pearl Harbor Memorial Highway outside metro Phoenix.

Avra Valley

The Avra Valley is a 50-mile (80 km) long northwest-southeast valley, bordering the west of Tucson, Arizona. The Tucson Mountains are at the valley's center-east, with suburbs ranging east of the Tucson Mountains and trending northwest to the Avra Valley's northeast. This entire northwest stretch from Tucson contains the northwest trending Interstate 10, the route to Casa Grande and Phoenix. The northeast of the valley contains Marana on I-10, the Pinal Airpark, an aircraft storage park, and other communities along I-10. Avra Valley Airport is a general aviation airport in Marana, located about 15 miles northwest of Tucson and being used for storage of classic propeller-era airliners.

Coronado National Forest

The Coronado National Forest is a United States National Forest that includes an area of about 1.78 million acres (7,200 km2) spread throughout mountain ranges in southeastern Arizona and southwestern New Mexico.

Both districts conserve tracts of the Sonoran Desert, including ranges of significant hills, the Tucson Mountains in the west and the Rincon Mountains in the east. [4] Elevations in the Tucson Mountain District range from 2,180 to 4,687 feet (664 to 1,429 m), [4] the summit of Wasson Peak. [19] The Tucson Mountain District receives an average of about 10 inches (250 mm) of precipitation a year. [4] Elevations within the Rincon Mountain District vary from 2,670 to 8,666 feet (814 to 2,641 m) [4] at the summit of Mica Mountain, where annual rain and snow totals average 30 inches (760 mm). [20] Precipitation in both districts falls mainly during two brief seasons, in December and January as steady light rains and in July and August as brief violent rains accompanied by lightning and sometimes by dust storms and flash floods. [21] Some moisture at the highest elevations in the Rincons falls as snow in winter; snowmelt adds to the limited water available at lower elevations later in the year. [22]

Between October and April, daytime temperatures reach 70 to 80 °F (21 to 27 °C), and nighttime temperatures may drop below freezing. [19] During the warmest season, May through September, daily high temperatures average more than 100 °F (38 °C). [19] Studies of the effects of climate change on the park show that its annual mean temperature rose from about 63 °F (17 °C) in 1900 to about 67 °F (19 °C) in 2010. [23] [24]

Saguaro National Park lies within the watershed of the north-flowing Santa Cruz River, [25] which is generally dry. [26] Rincon Creek in the southern part of the Rincon Mountain District, free-flowing for at least part of the year, has the largest riparian zone in the park. The creek is a tributary of Pantano Wash, which crosses Tucson from southeast to northwest to meet Tanque Verde Wash. The two washes form the Rillito River, another dry wash, [6] an east–west tributary of the Santa Cruz River. [16] The washes in both districts are usually dry but are subject at times to flash floods. [27] Smaller riparian zones are found near springs and tinajas in the Rincon Mountain District. [28] The largest of the springs is at Manning Camp, high in the Rincons. [29]

Geology

Catalina gneiss, the most common rock type in the Rincons, is exposed at Javelina Rocks along the Cactus Forest Loop Drive in the Rincon Mountain District. Javelina Rocks in the RMD.jpg
Catalina gneiss, the most common rock type in the Rincons, is exposed at Javelina Rocks along the Cactus Forest Loop Drive in the Rincon Mountain District.

Saguaro National Park's oldest rocks, the Pinal Schist, pre-date the formation of the contemporary Basin and Range Province, of which the park is a part, by about 1.7 billion years. [30] The schist is exposed in the Rincon Mountain District along a dry wash off Cactus Forest Loop Drive. [31] Other ancient rocks, 1.4-billion-year-old altered granites, form much of Tanque Verde Ridge [30] in the Rincon Mountain District.

Much later, about 600 million years ago, shallow seas covered the region around present-day Tucson; over time that led to deposition of sedimentary rockslimestones, sandstones, and shales. [30] Limestone, which occurs in the park in several places, was mined here in the late 19th century to make mortar. [30] The future park land had six lime kilns, two in the Tucson Mountain District, and four in the Rincon Mountain District. Three, all in the Rincon Mountain District, can be visited today—two along the Cactus Forest Trail and one along the Ruiz Trail. [32]

About 80 million years ago tectonic plate movements induced a period of mountain building, the Laramide orogeny, which lasted until about 50 million years ago in western North America. Explosive volcanic eruptions formed the Tucson Mountains about 70 million years ago, [33] and the roof of the volcano at their center collapsed to form a caldera 12 miles (19 km) across. [34] The caldera was eventually filled by debris flows, the intrusion of a granitic pluton, and lava flows, some as recent as 30 to 15 million years ago. [34] Volcanic rocks exposed in and near the Tucson Mountain District are remnants of these events. [33] Examples include large breccia exposed at Grants Pass and a granitic remnant of the magma chamber, which is visible from the Sus Picnic Area in the Tucson Mountain District. [35] Not all of the molten granite reached the surface of the Tucson Mountains; some cooled and crystallized far below. [33]

The Tucson Basin and nearby mountains—including the Tucson Mountains to the west, the Santa Catalinas to the north, and the Rincons to the east—are part of the Basin and Range Province extending from northern Mexico to southern Oregon in the United States. [33] The province, of relatively recent geologic origin, formed when plate movements stretched and thinned the Earth's crust in this part of western North America until the crust pulled apart along faults. [33] The Catalina Fault, a low-angle detachment fault, began to form about 30 million years ago about 6 to 8 miles (10 to 13 km) below the surface of the Tucson Mountains. [36] The rocks under the fault, the lower-plate rocks, were eventually displaced 16 to 22 miles (26 to 35 km) east-northeast relative to the rocks above the fault, then uplifted, domed, and eroded to form the Santa Catalina and Rincon mountains visible today. [34] Although the volcanic rocks seen on the surface of the Tucson Mountain District are not found in the Rincon Mountain District, [30] the crystallized granite (Catalina gneiss) from beneath the Tucson Mountains was eventually exposed on the Rincon Mountain District's surface. [34] The most common rock type in the Rincon Mountains, this banded gneiss is visible in the Rincon Mountain District at sites such as Javelina Rocks along the Cactus Forest Loop Drive. [37]

History

Early

Hohokam petroglyphs in the Tucson Mountain District Sunshine-AZ Photo Saguaro Park West Petroglyphs.jpg
Hohokam petroglyphs in the Tucson Mountain District

The earliest known residents of the land in and around what later became Saguaro National Park were the Hohokam, who lived there in villages between 200 and 1450 A.D. Petroglyphs and bits of broken pottery are among Hohokam artifacts found in the park. [38] The Hohokam hunted deer and other animals, gathered cholla buds, prickly pears, palo verde pods, and saguaro fruit, and grew corn, beans, and squash. Subsequent indigenous cultures, the Sobaipuri of the Tucson Basin and the Tohono O'odham to the west, may be descendants of the Hohokam, [39] though the evidence is inconclusive. [40]

Spanish explorers first entered Arizona in 1539–40. [39] Non-native settlement of the region near the park did not occur until 1692 with the founding of San Xavier Mission along the Santa Cruz River, [39] [41] which flowed through Tucson. [26] In 1775, the Spaniards built Presidio San Agustín del Tucsón, a military fort in what was then part of New Spain, [42] in part to protect against raids by Apaches. [39]

The lands that eventually would become Saguaro National Park remained relatively free of development until the mid-19th century, after Arizona had become part of the United States. After passage of the Homestead Act of 1862, the arrival of the railroad in 1880, and the end of the Apache Wars in 1886, homesteaders and ranchers established themselves in the Tucson and Rincon Mountains, and miners sought silver, copper, and other valuable ores and minerals. [39] Mining in the park continued intermittently through 1942, [43] while ranching on private in-holdings within the park continued until the mid-1970s. [44]

The defunct Loma Verde Mine, which is still visible in the Rincon Mountain District, [39] produced a small amount of copper and gold between 1897 and 1907. [45] Mining of igneous rock at 149 sites in the Tucson Mountain District sometimes produced ores of modest value in the late 19th and early 20th centuries. [46] The most successful, the Copper King Mine (later renamed the Mile Wide Mine), yielded 34,000 tons of copper, gold, lead, zinc, and molybdenum ores, mostly during the war years of 1917, 1918, and 1941; it closed permanently in 1942 when it became unprofitable. [43]

Ranchers grazed thousands of cattle on public land that would later become part of the park, and homesteaders farmed and ranched at the base of the Rincons, [39] filing homestead applications from the 1890s through 1930. [47] The remains of the former Freeman Homestead, established in 1929, lie along a nature trail in the Rincon Mountain District. The homestead is on the Arizona State Register of Historic Places. [47] Manning Cabin, built in 1905 as a summer retreat for Levi Manning, a wealthy businessman and one-term mayor of Tucson, is part of the infrastructure at Manning Camp near Mica Mountain. [39] [48] Modified and restored after falling into disrepair, it was added to the National Register of Historic Places in 1975. [48] Cultural resources in the park include more than 450 archeological sites and more than 60 historic structures. [49]

After 1920

Saguaro National Monument (now the Rincon Mountain District) in 1935 Saguaro National Park1935.jpg
Saguaro National Monument (now the Rincon Mountain District) in 1935

In 1920 members of the Natural History Society of the University of Arizona expressed interest in establishing a protected area for saguaro, a cactus species familiar to watchers of silent-movie Westerns. In 1928 Homer L. Shantz, a plant scientist and the university's president, joined the efforts to create a saguaro sanctuary, [50] but issues related to funding and management delayed the creation of a park. In 1933 Frank Harris Hitchcock, publisher of the Tucson Citizen and a former United States Postmaster General who was influential in the Republican Party, persuaded U.S. President Herbert Hoover to create Saguaro National Monument. [51] Hoover used his power under the Antiquities Act of 1906 to create the monument by proclamation on March 1, 1933. [52] [53] Later that year President Franklin D. Roosevelt transferred management of the monument, east of Tucson in the Rincon Mountains, to the National Park Service. [50] Between 1936 and 1939, during the Roosevelt administration, the Civilian Conservation Corps (CCC) built the monument's Cactus Forest Loop Drive and related infrastructure. [54] The monument's visitor center opened in the 1950s. [50]

In 1961 President John F. Kennedy—encouraged by Stewart Udall, an Arizonan who was then Secretary of the Interior—added 16,000 acres (6,500 ha) of cactus lands in the Tucson Mountains to the monument. [50] This western district of the monument was carved from Tucson Mountain Park, managed by Pima County. In the 1920s, the Tucson Game Protective Association had persuaded the Department of the Interior to withdraw about 30,000 acres (12,000 ha) in the Tucson Mountains from homesteading and mining and to set it aside as a park and game refuge. Land leased by the county in this set-aside became the Tucson Mountain Recreation Area in 1932. Between 1933 and 1941 CCC workers built structures at eight picnic areas in the county-park portion of the set-aside, five of which later became part of the Tucson Mountain District of the national monument. Their other projects involved road- and trail-building, landscaping, erosion control, and enhancing water supplies for wildlife. Kennedy's 1961 proclamation created the Tucson Mountain District from the northern part of the county park and renamed the original monument lands east of Tucson the Rincon Mountain District. [13] Expansions in 1976 and 1994 brought the total Tucson Mountain District area to 24,818 acres (10,043 ha). In 1994 Congress elevated the combined Tucson Mountain District and Rincon Mountain District to National Park status. [50]

Rincon mountains from edge of tucson.jpg
Panorama of the Rincon Mountains. The houses and vegetation in the foreground are in Pima County, a few blocks east of the eastern boundary of Tucson.

Biology

Plants and fungi

Fairy duster, a low flowering shrub native to the park Fairy duster Saguaro NP.jpg
Fairy duster, a low flowering shrub native to the park

Plant communities within the park vary with elevation. The Tucson Mountain District has two distinct communities, desert scrub [4] —such as fourwing saltbush [55] and brittlebrush [56] —at the lowest elevations, and desert grassland a little higher. The Rincon Mountain District includes these two communities as well as four more at higher elevations, oak woodland, pine–oak woodland, pine forest and, high in the Rincons, mixed conifer forest [4] Douglas-fir, Ponderosa pine, white fir, Gambel oak, and many other trees, shrubs, and understory plants. [57] During annual inventories in 2011 and 2013, hundreds of scientists and thousands of volunteers identified 389 species of vascular plants, 25 of non-vascular plants, and 197 species of fungi in Saguaro National Park. [58]

Saguaros, which flourish in both districts of the park, grow at an exceptionally slow rate. The first arm of a saguaro typically appears when the cactus is between 50 and 70 years old though it may be closer to 100 years in places where precipitation is very low. Saguaros may live as long as 200 years and are considered mature at about age 125. [59] A mature saguaro may grow up to 60 feet (18 m) tall and weigh up to 4,800 pounds (2,200 kg) when fully hydrated. [5] The total number of saguaros in the park is estimated at 1.8 million, [60] and 24 other species of cactus are abundant. The most common of these are the fishhook barrel, staghorn cholla, pinkflower hedgehog, Engelman's prickly pear, teddybear cholla, and jumping cholla. [61]

Invasive plants include fountain grass, tamarisk, Malta starthistle, and many others, but by far the most severe threat to the native ecosystem is buffelgrass. [62] This drought-tolerant plant, native to parts of Africa and Asia, was imported to the United States in the 1930s and planted near Tucson and elsewhere to create cattle forage and to control erosion. First detected in the park in 1989, it has dispersed widely in both districts. Competing with other plants for sustenance, buffelgrass fills the empty spaces normally found between native desert plants and creates a significant fire hazard. The noxious weed, considered impossible to completely eliminate, is managed in some areas of the park and in Tucson residential zones by hand-pulling and, during periods of wet weather, application of glyphosate-based herbicides. [63]

A view of Saguaro National Park's natural landscape. Saguaro National Park.jpg
A view of Saguaro National Park's natural landscape.

Animals

Javelina in Saguaro National Park. The hoofed animal is native to the park. Javelina in Saguaro National Park.jpg
Javelina in Saguaro National Park. The hoofed animal is native to the park.

An inventory of medium and large mammals in the park confirmed the presence of 30 species in Saguaro National Park between 1999 and 2008. Of these, 21 were found in the Tucson Mountain District and 29 in the Rincon Mountain District. [64] A partial list of the park's mammals includes cougars, coyotes, bobcats, white-tailed deer, mule deer, javelinas, gray foxes, black-tailed jackrabbits, desert cottontails, ring-tailed cats, white-nosed coatis, ground squirrels, and packrats. [65] One endangered mammal, the lesser long-nosed bat, lives part of the year in the park and part of the year in Mexico. [66]

The wide range of habitats in the park supports a diverse population of birds including some, such as the vermilion flycatcher and the whiskered screech owl, uncommon elsewhere in the United States. [67] Among the park's 107 bird species [58] are great horned owls, cactus wrens, ravens, kestrels, turkey vultures, roadrunners, woodpeckers, hawks, quails, and hummingbirds, [68] and one threatened species, the Mexican spotted owl. [69]

The park's 36 reptile species [58] include desert tortoises, diamondback rattlesnakes (one of the more commonly seen snakes), coral snakes, Gila monsters, short-horned lizards, spiny lizards, and zebra-tailed lizards. [70] Despite the aridity, three amphibian species inhabit the park: [58] the canyon tree frog, the lowland leopard frog, and Couch's spadefoot, which lives in underground burrows, emerging to breed during summer rains. [71] Forest fires, which create erosion-prone burned areas, have destroyed many of the leopard frog's breeding pools, which fill with sediment. The Arizona Game and Fish Department lists the lowland leopard frog as a species of special concern. [72]

Urban sprawl, air and water pollution, noise, light pollution, and a range of habitat restricted by human infrastructure put stress on the park's mammals and other animals, but the most serious immediate threat to them is roadkill. About 50,000 vertebrates a year die on the park's roads when they are hit by a vehicle. The Rincon Mountain District has few roads, but Picture Rocks Road, an east–west commuter highway crossing the Tucson Mountain District, is highly dangerous to wildlife. Attempts in 2002 to convert it to a hiking trail failed after the proposal met with stiff public resistance. [73]

Sky Islands

The Rincons and the nearby Santa Catalinas (but not the shorter Tucson Mountains) are among about 40 mountain ranges known as the Madrean Sky Islands that are of special interest to biologists. [74] These ranges, resembling a series of stepping stones between the southern end of the Rocky Mountains—specifically the Mogollon Rim of the Colorado Plateau—in the United States and the Sierra Madre Occidental in Mexico, are continental "islands" separated from one another by "seas" of lower-elevation valleys that impede but do not completely block species migration from one sky island to another. Ecologist Peter Warshall lists several characteristics that make the Madrean complex unique among Earth's 20 or so sky-island complexes. Among these are its north–south orientation across eight degrees of latitude spanning zones from the temperate to the subtropical, the highly varied nature of its geologic origin and of its soils, the moderate to high relief of its terrain, and its safe distance from the mass extinctions related to the northern glaciers of the most recent Ice Age. Influenced by these and other conditions, the Madrean Sky Islands support unusual biodiversity. [75]

Recreation

The park is generally open to hikers all day every day except Christmas; the Tucson Mountain District is open to vehicle traffic from sunrise to sunset and the Rincon Mountain District from 7 a.m. to sunset. Both districts have visitor centers. [76] More than 165 miles (266 km) of hiking trails wind through the park, [77] where perils may include extreme heat, dehydration, flash floods, cactus spines, snakes, cougars, bears, and Africanized bees. [78] The Rincon Mountain District is open to wilderness camping, which requires a permit, [18] [79] but no overnight camping is permitted in the Tucson Mountain District. [80]

Tucson Mountain District

Map of the Tucson Mountain District showing entrances, roads, buildings, trails, picnic areas, and surrounds TMD trail map.png
Map of the Tucson Mountain District showing entrances, roads, buildings, trails, picnic areas, and surrounds

The Tucson Mountain District has 12 miles (19 km) of paved roads and 8.5 miles (13.7 km) of unpaved roads, [81] including the 5-mile (8 km) Bajada Loop Drive. [19] Bicycling is allowed only on paved roads, as well as Bajada Loop Drive, Golden Gate Road, and the Belmont multi-use trail. [82] [83] Horses and other livestock are allowed on some of the trails. [82]

Hohokam petroglyphs etched into large stones are easily accessible in the Tucson Mountain District. The Signal Hill Trail, which begins at the Signal Hill Picnic Area along the Bajada Loop Drive, leads to an area with dozens of examples of the 800-year-old rock art. [84]

Among the notable artificial structures in the Tucson Mountain District are ramadas, picnic tables, and restrooms built by the Civilian Conservation Corps between 1933 and 1941. Designed to conform to their natural surrounds, the rustic buildings consist mainly of quarried stone and other materials native to the area. [85]

The Arizona-Sonora Desert Museum lies just south of the Tucson Mountain District along North Kinney Road in Tucson Mountain County Park. The non-profit organization, operating on 98 acres (40 ha) rented from Pima County, combines aspects of a botanical garden, zoo, and natural history museum featuring the plants and animals native to the region. [86]

Rincon Mountain District

Map of the Rincon Mountain District showing entrances, roads, buildings, trails, picnic areas, campsites, and surrounds Rincon Mountain District map.png
Map of the Rincon Mountain District showing entrances, roads, buildings, trails, picnic areas, campsites, and surrounds

The Rincon Mountain District features the 8.3-mile (13.4 km) Cactus Forest Loop Drive, which provides access to some of the trails. [54] [82] Angling across the Rincon Mountain District from southwest to northeast is a segment of the Arizona Trail. [87] The 800-mile (1,300 km) trail crosses Arizona from its border with Mexico on the south to its border with Utah on the north. In 2009, Congress named it a National Scenic Trail. [88]

Horseback riding is allowed on some of the trails. [82] Livestock—defined by the NPS as horses, mules, or burros—must carry their own food and are not allowed to graze in the park. [80] Bicycling is allowed on the Cactus Forest Loop Drive and two park trails. [82] [83]

Manning Camp Campground is the main staging area for firefighters, trail-maintenance crews, and scientists working in the Rincon Mountain District. Their supplies are brought in by pack mules that are kept in corrals at the site. [18] Runoff from a nearby spring, the largest in Rincons, provides water for the livestock. [29]

On a 40-acre (16 ha) plot adjacent to the Rincon Mountain District along Broadway, the Desert Research Learning Center (DRLC) supports scientific and educational projects related to a network of Sonoran Desert parks, including Saguaro National Park. The DRLC grounds, which include desert plants, an artificial tinaja, and a rainwater collection system, are open to the public. [89] The Sonoran Desert Inventory and Monitoring Network of which the DRLC is part, covers 10 national monuments or parks in Arizona and 1 in New Mexico. [90]

See also

Related Research Articles

Southwestern United States Geographical region of the USA

The Southwestern United States, also known as the American Southwest, is the informal name for a region of the western United States. Definitions of the region's boundaries vary a great deal and have never been standardized, though many boundaries have been proposed. For example, one definition includes the stretch from the Mojave Desert in California to Carlsbad, New Mexico, and from the Mexico–United States border to the southern areas of Colorado, Utah, and Nevada. The largest metropolitan areas are centered around Phoenix, Las Vegas, Tucson, Albuquerque, and El Paso. Those five metropolitan areas have an estimated total population of more than 9.6 million as of 2017, with nearly 60 percent of them living in the two Arizona cities—Phoenix and Tucson.

Sonoran Desert North American desert

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, and Baja California Sur. It is the hottest desert in Mexico. It has an area of 260,000 square kilometers (100,000 sq mi). The western portion of the United States–Mexico border passes through the Sonoran Desert.

Organ Pipe Cactus National Monument national monument in the United States

Organ Pipe Cactus National Monument is a U.S. National Monument and UNESCO biosphere reserve located in extreme southern Arizona that shares a border with the Mexican state of Sonora. The park is the only place in the United States where the organ pipe cactus grows wild. Along with organ pipe, many other types of cacti and other desert flora native to the Yuma Desert section of the Sonoran Desert region grow in the park. Organ Pipe Cactus National Monument is 517 sq mi (1,340 km2) in size. In 1976 the monument was declared a Biosphere Reserve by UNESCO, and in 1977 95% of Organ Pipe Cactus was declared a wilderness area.

Yuma Desert

The Yuma Desert is a lower-elevation section of the Sonoran Desert in the southwestern United States and the northwest of Mexico. It lies in the Salton basin. The desert contains areas of sparse vegetation and has notable areas of sand dunes. With an average rainfall less than 8 inches (200 mm) each year, this is among the harshest deserts in North America. Human presence is sparse throughout, the largest city being Yuma, Arizona, on the Colorado River and the border of California.

Tonto National Monument national monument in Gila County, Arizona

Tonto National Monument is a National Monument in the Superstition Mountains, in Gila County of central Arizona. The area lies on the northeastern edge of the Sonoran Desert ecoregion, an arid habitat with annual rainfall of about 16 inches (400 mm) here. The Salt River runs through this area, providing a rare, year-round source of water.

Tumamoc Hill

Tumamoc Hill is a butte located immediately west of "A" Mountain and downtown Tucson, Arizona. It is home to many radio, television, and public safety transmitters. The 860-acre ecological reserve and U.S. National Historic Landmark was established by the Carnegie Institution in 1903. The University of Arizona (UA) owns a 340-acre (1.4 km2) preserve and leases another 509 acres (2.06 km2) as a research and education facility. The Steward Observatory maintains a small astronomical observatory with a 20-inch (510 mm) telescope on the hill. Besides being a prominent landmark, Tumamoc Hill has a long and varied history, and is currently an important site for ecological and anthropological research as well as a refuge and a recreational option for the people of Tucson. The Desert Laboratory located on Tumamoc welcomed a new director, Ben Wilder, as of 2018.

Ironwood Forest National Monument national monument in the Sonoran Desert of Arizona

Ironwood Forest National Monument is located in the Sonoran Desert of Arizona. Created by Bill Clinton by Presidential Proclamation 7320 on June 9, 2000, the monument is managed by the Bureau of Land Management, an agency within the United States Department of the Interior. The monument covers 188,619 acres (76,331 ha), of which 59,922 acres (24,250 ha) are non-federal and include private land holdings and Arizona State School Trust lands.

Index of Arizona-related articles

The following is an alphabetical list of articles related to the U.S. state of Arizona.

Pinnacle Peak (Arizona) mountain in United States of America

Pinnacle Peak is a granite summit located in Scottsdale, Arizona. The peak rises to an elevation of 3,169 feet (966 m). It is located within the 150-acre (61 ha) Pinnacle Peak Park, operated by the City of Scottsdale Park District. Part of the Sonoran Desert, the park is home to a variety of native desert flora and fauna. Hikers utilize a 1.75 mile trail to explore the area, though rock climbing skills are needed to reach the summit.

Oracle State Park

Oracle State Park is a state park of Arizona, USA, preserving 3,948 acres (1,598 ha) in the northeastern foothills of the Santa Catalina Mountains. The park is named after the nearby town of Oracle. Oracle State Park serves as a wildlife refuge, and is open every day from 9am - 5pm. In October 2011 Arizona State Parks agreed to reopen Oracle on a limited basis with a $40,000 budget if the park's Friends group can raise $21,000 in additional funds. The park has more than 15 miles (24 km) of hiking trails, including 7 miles (11 km) of the Arizona Trail.

Geography of Arizona

Arizona is a landlocked state situated in the southwestern region of the United States of America. It has a vast and diverse geography famous for its deep canyons, high- and low-elevation deserts, numerous natural rock formations, and volcanic mountain ranges. Arizona shares land borders with Utah to the north, the Mexican state of Sonora to the south, New Mexico to the east, and Nevada to the northwest, as well as water borders with California and the Mexican state of Baja California to the southwest along the Colorado River. Arizona is also one of the Four Corners states and is diagonally adjacent to Colorado.

Silver Bell Mountains

The Silver Bell Mountains are an arid north-northwest x southeast trending small mountain range in north-central Pima County, Arizona. The range lies 14 miles (23 km) west of Marana, Arizona, located on Interstate-10, northwest of Tucson.

West Silver Bell Mountains

The West Silver Bell Mountains are a small 10 mile (16 km) long mountain range of south-central Arizona, United States. The range lies in the north-central arid Sonoran Desert; the Madrean Sky Islands region of southeast Arizona, around Tucson is adjacent to the southeast.

Cocoraque Butte Archaeological District place in Arizona listed on National Register of Historic Places

The Cocoraque Butte Archaeological District is located in Ironwood Forest National Monument, in Pima County, Arizona. Added to the National Register of Historic Places on October 10, 1975, the Cocoraque Butte Archaeological District features ancient Hohokam ruins, hundreds of well-preserved petroglyphs, and the historic Cocoraque Ranch.

Mica Mountain

Mica Mountain is a 8,668-foot (2,642 m) peak in the Rincon Mountain District of Saguaro National Park in Pima County, Arizona, about 20 miles (32 km) east of Tucson. It is the highest point of the park and the highest point in the Rincon Mountains.

San Tan Mountains Regional Park

San Tan Mountains Regional Park is a large urban park located in Pinal County. It encompasses over 10,000 acres and preserves a portion of the San Tan Mountains, south of Queen Creek.

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