Saguaro National Park
Split into the separate Rincon Mountain and Tucson Mountain districts, this park is evidence that the dry Sonoran Desert is still home to a great variety of life spanning six biotic communities. Beyond the namesake giant saguaro cacti, there are barrel cacti, chollas, and prickly pears, as well as lesser long-nosed bats, spotted owls, and javelinas.
Both the Tucson Mountain District and the Rincon Mountain District contain features distinctive to the geological processes in the southwestern desert environment
The Tucson Mountains Caldera is the eroded remains of a colossal volcanic eruption that occurred approximately 70 to 75 million years ago.
The Rincon Mountain District provides one of the best exposures of a metamorphic core complex in western North America. Unique to the mountainous North American Cordillera, metamorphic core complexes consist of metamorphosed basement rocks overlain by unmetamorphosed rock units. Rock outcrops along Cactus Forest Drive are considered to be the “showpiece” of diagnostic features of metamorphic core complexes, and the geology of the Rincon Mountain District served as the basis for distinguishing and classifying the fundamental structural characteristics of metamorphic core complexes.
Both the Tucson Mountain District and the Rincon Mountain District contain features distinctive to the geological processes in the southwestern desert environment, such as pediments, alluvial fans, bajadas, and rock varnish. In addition, tectonic and depositional features that represent various plate tectonic episodes are present in both districts.
Tinajas are ephemeral pools in either unconsolidated deposits or bedrock. They are important water sources for wildlife, particularly the leopard frog.
Cambrian-aged marine invertebrates (brachiopods and trilobites) have been discovered within the park although they are not abundant (Tweet et al. 2008). Packrat middens are also known from the park and are important components of regional paleoecology studies. Potential exists for new and continued fossil discoveries.
All NPS fossil resources are protected under the Paleontological Resources Preservation Act of 2009 (Public Law 111-11, Title VI, Subtitle D; 16 U.S.C. §§ 470aaa – 470aaa-11).
Cave and Karst
Tilted beds of Permian and Pennsylvanian age Horquilla limestone (320 million years to 245 million years old) and the Mississippian age Escabrosa limestone (359 million years to 323 million years old) are exposed at the surface in the Tucson Mountains District. One cave has been reported in the area.
All NPS cave resources are protected under the the Federal Cave Resources Protection Act of 1988 (FCRPA)(16 U.S.C. § 4301 et seq.).
Flooding and debris flows have been major issues in the past and will likely continue to be in the future. Events with estimated recurrence intervals of hundreds to more than a thousand years occurred during the summers of 2005 and 2006. Flooding and debris flows are more typical after fire has removed stabilizing vegetation, but those in 2006 showed that fire is not necessary for major debris flows.
Potential Threats: Flooding and debris flows can impact landforms in the park, accelerate erosion, as well as limit access and create visitor safety issues. Occasionally, debris flows wash out roads within the park causing temporary closures. Sediment moved via debris flows or other slope processes may contribute to tinaja sedimentation.
Abandoned Mineral Lands
Saguaro has a rich mining history and evidence of past mining can be seen in several areas. The Servicewide AML Database indicates that the park has 177 AML sites with 541 individual features. The sites inventoried are related to underground mines that were predominantly mined for gold, silver, copper, and lead. These sites are considered hazardous due to native metal contaminants and unstable conditions.
NPS AML sites can be important cultural resources and habitat, but many pose risks to park visitors and wildlife, and degrade water quality, park landscapes, and physical and biological resources. Be safe near AML sites—Stay Out and Stay Alive!
Geology Field Notes
Students and teachers of college-level (or AP) introductory geology or earth science teaching courses will find that each park’s Geologic Resource Inventory report includes the Geologic History, Geologic Setting, and Geologic Features & Processes for the park which provides a useful summary of their overall geologic story. See Maps and Reports, below.
Saguaro National Park is a part of the Basin and Range Physiographic Province and shares its geologic history and some characteristic geologic formations with a region that extends well beyond park boundaries.
see original article here: https://www.nps.gov/articles/nps-geodiversity-atlas-saguaro-national-park-arizona.htm
Native American History
Home of the Hohokam peoples
Most southwestern rock art pre-dates modern written history and had it’s origins hundreds, perhaps thousands, of years ago, created by the people of this region. Most of the rock art found in Saguaro National Park was created by the prehistoric Hohokam and is in the form of petroglyphs. These are created by etching, pecking or scraping designs into the dark patina found on the surface of sandstone and other rocks.
Both representational and abstract designs can be seen in Hohokam petroglyphs. Representational images are often animals, humans and astrological objects.
Abstract designs take many forms, including spirals and squiggly lines.
What Does it Mean?
Did rock art serve a purpose? Was it communication or decoration? We can only guess at the intended meaning of the artist. We may look at rock as a reflection of Hohokam culture. Some possible purposes of rock art include: hunting, fertility or spiritual symbols; boundary markers or landmarks; records of important events; clan symbols; and solstice and calendar markers.
Where Can I see Petroglyphs in Saguaro National Park?
Petroglyphs can easily be seen by walking the Signal Hill Trail in the Tucson Mountain District (West). Starting from the Signal Hill Picnic Area, the trail gently climbs to a hill covered with dozens of 800-year-old petroglyphs.
Help Preserve Our Petroglyphs!
Oils from your hands can actually damage the petroglyphs. We invite you to take lots of photographs, but please don’t leave any fingerprints.
see original article here: https://www.nps.gov/sagu/learn/historyculture/petroglyphs.htm
How Saguaro became a National Park
Herbert Hoover declared this land a National Monument on March 1st, 1933.
Becoming a Park
Congress officially elevated the area known as Saguaro National Monument to the current designation as a National Park in 1994. The land addition on the southern border of the Rincon Mountain District occurred that same year and with gracious land donations from time to time we have increased to our current land area.
Saguaro Cactus State Park
By 1930 the ill-fated Papago Saguaro National Monument was no more and the area was turned over to the state. The National Park Service was now in search of a new monument for the protection of the Sonoran Desert ecosystem. Local Tucson conservationists and scientists, such as U. of A. President Homer Shantz, were already looking to preserve a portion of unspoiled Sonoran desert along with its iconic saguaro cacti. In 1928-29, one priority of the Tucson Natural History Society was the preservation of the locally known Tanque Verde Cactus Forest. The forest occupied over a dozen square miles on the bajada at the foot of the Rincon Mountains. By 1930 University of Arizona President Homer Shantz felt the time had come to push the agenda through the private avenues of land purchase. By August 1931 the University had an investment of twenty one thousand dollars and had a lease on four and three-quarter sections. By 1935 The University either owned or leased from the State of Arizona 10.5 sections (6,560 acres) of land in the Cactus Forest of the newly established Saguaro National Monument. At that time the monument was a tapestry of federal, state and private land.
Because of the Great Depression, the university decided it needed to recoup the money it had spent on its so-called Saguaro Forest State Park. The University approached the Park Service about the prospects of them purchasing the land but the Park Service had no money for such purchases. Arizona Senator Carl Hayden introduced several bills in the U.S. Senate that would authorize acquisition of state, university, and private land. Hayden introduced the first bill in 1937, and introduced similar bills again in 1939, 1941, 1943, and 1945. The bills failed because it was again thought that the cost of the land was too high. Finally, in 1948 the U.S. Government and the state entered into land exchange negotiations by which the state and University would exchange their land within the monument for other federally owned land. By early 1956 the exchange was finally completed except for half of the University land (240 acres). The last of the University land was acquired by trade in 1959.
Tucson Mountain Park
On November 15, 1961, the Tucson Mountain District (TMD) (15,360 acres) was added to Saguaro National Monument (made a National Park in 1994). Prior to its transfer to Saguaro National Monument, this area was part of Pima County’s Tucson Mountain Park. In the 1920s the Tucson Game Protective Association headed by C.B. Brown became fearful that the encroachment of homesteads in the Tucson Mountains would leave no place of natural beauty for the area residents to enjoy. The Association, backed by many prominent people, started a movement to have the area withdrawn from homesteading and set aside as a park and game refuge. They were successful when on April 29, 1929 the department of the Interior issued Recreation Withdrawal Order 21 on 29,988 acres, preventing mineral and homestead entry. Pima County obtained a lease on 15,787.90 acres of that land on December 15, 1930; a supplemental lease provided the remainder on May 4, 19311 . A formal opening was held for the Tucson Mountain Recreation Area on April 10, 1932.
Tucson Mountain Park was a mix of county owned and county leased federal lands. Pima County’s lease of these federal lands ran out in 1957 (Arizona Daily Star 1959) and based on an August 6, 1955 request from the Banner Mining Company a decision was made by the federal government not to extend the lease. In response to the 1955 request from the Banner Mining Company (Arizona Daily Star 1959) to the Bureau of Land Management, the U.S. Department of the Interior announced on September 9, 1959 (Arizona Daily Star 1959) the withdrawal, for mineral exploration, 7600 acres of federally owned land that comprised part of Tucson Mountain Park. At once an intense debate began regarding whether or not the withdrawal should be allowed to happen and what the impact of renewed mining would have in this part of the Tucson Mountains. Bowing to public pressure, the decision to rescind the order came on December 17, 1959 (Arizona Daily Star 1961) but the debate of what to do with the federal lands continued. It was eventually decided that the federal lands that made up the northern portion of the park would be transferred to Saguaro National Monument, and by Presidential proclamation, dated November 15, 1961, the Tucson Mountain District was added to Saguaro National Monument.
see original article here: https://www.nps.gov/sagu/learn/historyculture/index.htm
Two Districts, One Park
Where do we begin? There is so much to take in while visiting this beautiful park. Saguaro National Park is home to one of the world’s most majestic plants – the Saguaro Cactus (scientific name Carnegiea gigantea). This Sonoran Desert native, is a large, tree-sized cactus with a relatively long lifespan – up to 250 years. Its beautiful white, waxy flower (which blooms late May-July) is the Arizona state flower and is a favorite treat for the diverse animal populations that call Saguaro National Park home.
Saguaro National Park has two districts – East & West – that are separated by the City of Tucson. It takes 30-45 minutes to transit between the two districts depending on route and traffic, so it is important you plan accordingly. Don’t worry, you only pay the entrance fee once, and your pass is good at both locations for 7 days from the date of purchase.
Each district has a variety of ranger led, guided programs you can choose from. Programs are similar from week to week, and are subject to change without notice. Some interpretive programs are accessible to persons with physical disabilities or require a reservation to participate. This information will be noted on the schedule along with a phone number to make a reservation or get more information.
see original article here: https://www.nps.gov/sagu/planyourvisit/things2do.htm
There is an abundance of plant life in Saguaro National Park
Saguaro National Park is located within a desert, but contrary to what you might expect, there is an abundance of life. Plants here are adapted to drought, so during long dry periods they are able to go dormant, conserving their water. At these times, many plants appear lifeless, but shortly after a rainfall these plants are able to come to life sprouting new green leaves. If you like green, you will especially enjoy Saguaro National Park during the rainy seasons. Within just 48 hours after a rainfall, the ocotillo plant is able to change from what appeared to be a handful of dead sticks into a cheerful shrub with tall green branches, covered in new leaves.
The varied elevation within the park allows for a great variety of different species. Current research indicates there are approximately 1200 species in the Rincon Mountain District and approximately 400 species in the Tucson Mountain District. A precise number is difficult to ascertain given the complexity of the topography for sampling uniformly and changes in taxonomy, and the voucher specimens housed in unknown locations.
Currently, there are no USFWS Threatened or Endangered plants within the park. The park does have rare and sensitive plant species. The park estimates there are approximately 80 non-native plant species some of which are quite invasive. The Restoration and Invasive Plant Management Program, with help from volunteers, maps and removes non-native invasive species from both districts of the park. See Invasive Plants to learn more about the invasive species of concern and how the park manages these harmful plants.
see original article here: https://www.nps.gov/sagu/learn/nature/plants.htm
Although the Sonoran Desert can seem foreboding, it is home to many animal species
Although the Sonoran Desert can seem foreboding, it is home to many animal species. These animals have adapted to the desert’s high temperatures and scarce water supply. Many species simply avoid the hot daytime temperatures by being active only at night or by seeking shelter in shaded nests or burrows. Others have features that allow them to stay cool – the jackrabbit’s large ears allow heat to radiate away from its body, and vultures actually urinate on themselves to dissipate heat!
Saguaro National Park contains a great variety of unusual animals, some of which can only be found in southern Arizona. Roadrunners, horned lizards, Gila monsters, kangaroo rats, and collared peccaries are all seen regularly by visitors. Although Saguaro NP lies on the edge of the Sonoran Desert, Mica Mountain in the Rincon Mountain District reaches more then 8600’ in height. This altitude allows for cooler temperatures and pine trees, as well as mammals such as black bears and white-tailed deer. The park is also home to species more commonly associated with the tropics, such as coati. Precious, often hidden desert waters contain aquatic leopard frogs and mud turtles.
see original article here: https://www.nps.gov/sagu/learn/nature/animals.htm
The best hiking trails in Saguaro National Park
Freeman Homestead Trail (1 mile)
Wander down this path to the site of an old homestead foundation, a grove of large saguaros and a cool desert wash. Great Horned Owls can often be seen in the cliff above this wash. Interpretive signs concerning the history and plant life along the way will take you deeper into the meaning of this “home in the desert”. These signs also feature special exploration activities for youngsters.
Loma Verde Loop (3.8 miles, 60 feet elevation)
From the trail head take the Loma Verde Trail north through a grove of mature mesquite trees. Beyond a seasonally flowing wash (pictured), you’ll climb a bluff onto the bajada, the Spanish word for a gravel plain at the base of a mountain. Pass the Loma Verde Mine, and take a right on the Pink Hill Trail. A short spur trail leads to a fine overlook of the cactus forest and Tanque Verde Ridge. Take a right on Pink Hill Trail, then turn right on the Squeeze Pen Trail. You will then take a left on the Loma Verde Trail and head back to the trail head.
Hope Camp and Ridgeview Trail (2 miles, 400 feet elevation)
From the Loma Alta trail head, take the Hope Camp trail for one-tenth of a mile until meeting the Ridge View Trail. This area was an old homesteading road and used to drive cattle to a line camp. Take a left on the Ridge View Trail, which begins to climb shortly after the junction. Views of Rincon Peak (pictured) begin after a brief slope, which only increase as you go up in elevation. Towards the end of the trail, incredible panoramic views and brilliant seasonal wildflowers fill the hillside. The trail ends at the top, which shows an incredible view into Box Canyon, a major drainage in the park. Waterfalls can be seen on the ridge during wetter times.
Garwood Dam and Wildhorse Tank (6.4 miles)
From the Douglas Spring trail head, continue until you take a right on the Garwood Trail (.2 mile). You’ll enter the kind of cactus forest that inspired the creation of this park in 1933. Stay on the Garwood trail until you hit the Carrillo trail, and take a left. A steep section will lead to the Garwood Dam, built by Nelson Gardwood in the 1950’s. Continue on Carrillo trail through a series of switch-backs until you start to get beautiful views on a ridge in the foothills. Beyond the ridge, you will intersect with Wildhorse Trail. Turn right to go on a steep (.3 mile) trail to Little Wildhorse Tank, one of the only perennial areas of water in the park. Continue back (right) onto Carrillo trail until you reach the steel tank. Continue down the wash and take a left out of the wash, still on the Carrillo trail. This section has incredible views of the Santa Catalina Mountains to the north. Finally, turn left and head down the Douglas Spring trail, bringing you back to the trail head.
Tanque Verde Ridge Trail (Distance and Elevation Varies)
This trail is certainly what we would describe as a strenuous trail. The views and seasonal wildflowers are certainly worth the hike up! From the Javelina Picnic area, start on the trail. At the .75 mile mark, you are up on the ridge and are able to see south, west, and north at multiple other mountain ranges and the Tucson Basin. A crested saguaro (at mile 2.5) is a unique view, as well as “the Dome” (a large exposed surface at mile 3) offers even more breath-taking views. This trail continues to Juniper Basin Campground (6.9 mile mark, 3000 feet elevation) as well as Tanque Verde Peak (8.7 miles, 4000 feet elevation).
Saguaro West (TMD)
Wild Dog Trail (1.8 miles)
Take the Valley View trail to the Wild Dog trail. This trail ends at the junction of Golden Gate Rd. & the turnoff to Signal Hill picnic area. If your group has hikers & non-hikers, the hikers could be dropped off at the beginning of the trail while non-hikers drive around the loop & pick them up at the end or at Signal Hill picnic ground. The Signal Hill road adds 0.5 miles to the hike.
King Canyon/ Gould Mine Loop (2.4 miles, 380 feet elevation)
Take the King Canyon Wash trail up the sandy wash bottom between the canyon walls to the junction & return via the King Canyon trail (an old mining road). There are several rocky “stair-step like” sections in the wash bottom. Also due to moisture, there may be bees present.
Sendero Esperanza Trail to the Ridge/ To Wasson Peak (3.4-8 miles, 220-1600 feet elevation)
Take the Sendero-Esperanza trail to the Hugh Norris trail junction on the ridgeline. The first mile is relatively flat, but quickly ascends up switch backs (220 feet elevation) towards the ridge. Great panoramic scenes of the valley come into view. If you’re up for it, take a left on the Hugh Norris Trail towards Wasson Peak. This is the high point for the west side of the park, at 4,687 feet. Continue for 1.9 miles and take the spur trial on the left .3 miles to Wasson Peak. Enjoy the incredible scenery!
see original article here: https://www.nps.gov/sagu/planyourvisit/saguaro_hiking.htm