Day 1 - Phoenix / Arizona

General

Phoenix is the capital and the largest city of Arizona, the fifth most populous city in the United States and the most populous state capital in the country. More than 1.6 million people were counted in the city at the 2020 census, and the metropolitan area, which reaches far beyond the city boundary across the Salt River Valley, is home to an estimated 5.19 million residents, the tenth most populous metropolitan area of the United States and the largest between Texas and California. Phoenix is the seat of Maricopa County and the cultural centre of the state.

The city lies in the south central part of Arizona, roughly halfway between Tucson to the south east and Flagstaff to the north, and about 240 kilometres north of the Mexican border at Sonoyta. Its mean elevation is 331 metres. With an area of 517.9 square miles, equivalent to 1,341 square kilometres, Phoenix is the largest city in Arizona by area and the eleventh largest in the United States. The floor of the valley is almost flat, which is why the main streets run on a precise grid of wide roadways. The name Valley of the Sun has been used for the Salt River Valley since the early 1930s.

Phoenix has a hot desert climate and is the largest city in the Americas in that category. It lies in one of the sunniest regions of the world and records 3,872 hours of bright sunshine a year, more than any other major city on Earth. On average there are 111 days a year with a high of at least 38 degrees Celsius, and 21 days above 43 degrees. The highest temperature ever recorded was 50 degrees on 26 June 1990. In July 2023 the city became the first major city in the United States with an average monthly temperature above 38 degrees.

The economy of the valley was built on what local accounts called the five C’s: cotton, cattle, citrus, climate and copper. They remained the driving forces of the city until after the Second World War, when high technology arrived and air conditioning made the long hot summers bearable in offices, factories and homes. The metropolitan product had reached more than 362 billion United States dollars by 2022. Phoenix averaged an annual population growth of about four per cent over four decades from the mid-1960s, and by 1980 it stood among the ten most populous cities of the country. About 42 per cent of its residents are of Hispanic origin.

Water is the quiet precondition of all of this. The Salt River and the reservoirs in the mountains east of the city feed the canals that turn the desert into farmland and gardens, and the outskirts of Phoenix still contain large fields of irrigated cropland as well as land belonging to Native American reservations. Tourism has been among the ten largest industries of the city for a century, with more than 19 million visitors a year, 175 hotels and nearly 28,000 rooms. Sky Harbor Airport handles about 45 million passengers, and more than 200 golf courses lie within the metropolitan area.

History

People have lived in the Salt River Valley for at least two thousand years. The Hohokam occupied the area for that long and built a system of irrigation canals about 217 kilometres in length, which carried river water onto fields and made farming possible in a desert. Parts of their routes were later used for the Arizona Canal, the Central Arizona Project Canal and the Hayden-Rhodes Aqueduct. They traded with the Ancestral Puebloans, the Mogollon and the Sinagua, and with peoples much further south in Mesoamerica. Drought and severe floods between 1300 and 1450 are thought to have ended their settlement of the valley.

After the Hohokam left, the valley was used by the Akimel O’odham, commonly known as the Pima, by the Tohono O’odham, by the Maricopa and in places by the Yavapai and Apache. The Akimel O’odham lived in small villages with their own irrigation systems along the Gila River, from Florence in the east to the Estrella Mountains in the west, and grew corn, beans and squash for food as well as cotton and tobacco. The Tohono O’odham, further south towards the Mexican border, farmed with the rains rather than with canals and gathered saguaro fruit, cholla buds and mesquite beans.

The region became part of the United States in 1848, at the end of the Mexican American War, when the territory north of the new border was ceded and its inhabitants became citizens. For a time the valley belonged to the New Mexico Territory. In 1863 the mining town of Wickenburg was founded to the north west of the present city, the first settlement in what would become Maricopa County, and in 1865 the army established Fort McDowell on the Verde River. A camp on the south side of the Salt River followed in 1866, the first permanent settlement in the valley since the decline of the Hohokam.

Modern Phoenix begins with Jack Swilling, a Confederate veteran of the Civil War who prospected near Wickenburg. Travelling through the Salt River Valley in 1867 he saw both the farming potential and the eroded mounds that marked the old canals, formed the Swilling Irrigation and Canal Company, dug a ditch and planted fields near what is now the eastern part of central Phoenix. Other settlers followed, attracted by fertile soil and the absence of frost. Darrell Duppa, one of the first of them, proposed the name Phoenix for a city born from the ruins of a former civilisation. The town was recognised in 1868 and incorporated as a city in 1881.

Phoenix became the capital of the Arizona Territory in 1889 and of the new state of Arizona on 14 February 1912, when it entered the Union as the forty-eighth state. The National Reclamation Act of 1902 made the first great dam possible: work on Salt River Dam Number One began in 1903, the structure was dedicated in May 1911 as the largest masonry dam in the world at the time, and it was renamed after Theodore Roosevelt in 1917. The city adopted a council-manager government in 1913 and counted 29,053 residents by 1920. After 1945 growth became explosive. Motorola opened a research centre in 1948 and was followed by Intel and McDonnell Douglas, and more was built in 1959 alone than between 1914 and 1946.

Geology

The valley is part of the Basin and Range Province, a physiographic region that covers much of the inland western United States and north western Mexico and is defined by abrupt changes of elevation, alternating between narrow faulted mountain chains and flat arid basins. The topography is the result of tectonic extension that began about 17 million years ago in the early Miocene. The Salt River Valley is one of the wider basins of that system, and the ranges around it are the tilted and faulted blocks of the same process, rising abruptly from a floor that lies at 331 metres.

Camelback Mountain, the highest peak in the metropolitan area at 2,704 feet, shows the structure clearly. Its summit is Precambrian granite about 1.5 billion years old, while the lower part known as the head of the camel is red sedimentary sandstone of the Chattian stage of the Oligocene, roughly 25 million years old. The two formations meet at an unconformity, a surface that stands for a gap of more than a billion years in the record. Similar rocks make up Piestewa Peak, North Mountain, Sunnyslope Mountain and the Phoenix Mountains, all of them inside the city boundary.

The Salt River is the largest tributary of the Gila and runs about 320 kilometres from its sources, formed by the confluence of the White River and the Black River in the White Mountains of eastern Arizona. Its drainage basin covers about 35,000 square kilometres, and the longest of its tributaries, the Verde River, is 314 kilometres long. The name comes from the salt deposits the river crosses shortly after the two headwater branches join. Within Phoenix the bed is often dry or nearly dry, because the water is taken out upstream for irrigation and for the supply of the cities.

Hohokam farmers worked with the same river and were defeated by it. Repeated floods in the middle of the fourteenth century deepened the bed of the Salt River and destroyed the heads of the canals, which had to be rebuilt or abandoned, and the agricultural system never recovered. Modern engineering answered the problem with storage. The dams built under the National Reclamation Act created the lakes in the mountains east of the city, and the canal system that grew out of them still carries water across the valley, supported since the 1970s by the Central Arizona Project and the Hayden-Rhodes Aqueduct, which bring Colorado River water into the basin.

The landforms between the ranges are typical of a hot desert. Alluvial fans spread from the mountain fronts, dry washes carry water only after the brief and violent summer storms that cause flash floods elsewhere in the state, and the older surfaces between them are covered in places with desert pavement, a closely packed layer of angular stones that shields the fine material below from the wind. Caliche, a hard cemented layer of calcium carbonate, lies under much of the desert floor, and the Hohokam used it, tempered with schist, granite and quartz, as adobe for their pit houses.

Things to See

Downtown Phoenix gathers most of the city’s museums and cultural institutions within a few blocks. The Phoenix Art Museum opened in November 1959 in a building designed by Alden B. Dow, a student of Frank Lloyd Wright, and holds more than 17,000 works, the largest collection of visual art in the south west. The Arizona Science Center, the Children’s Museum of Phoenix and the Rosson House in Heritage Square, a restored mansion of the 1890s, stand nearby. The Heard Museum, dedicated to the art and history of Native American peoples, has more than 130,000 square feet of galleries and attracts about 250,000 visitors a year.

The archaeology of the valley itself is on display at the Pueblo Grande Museum and Archaeological Park, which protects a Hohokam platform mound and a section of the prehistoric canal system that once watered the fields, and at the Arizona Museum of Natural History in neighbouring Mesa. The Hohokam left petroglyphs and stone structures in several of the mountain parks, and a cave on the north side of Camelback Mountain suggests that the peak was used as a sacred site before the culture abandoned the area in the fourteenth century.

Papago Park lies between Phoenix and Tempe and is best known for its weathered sandstone formations, above all the Hole in the Rock, a natural window in a small hill that frames the city beyond. The park covers 1,200 acres in its Phoenix part and another 296 acres in Tempe, and contains the Desert Botanical Garden as well as the Phoenix Zoo. The garden opened in 1939 and is one of the few public gardens in the world devoted entirely to desert plants. The zoo, the largest privately owned non profit zoo in the country, is known for its programmes for endangered species.

The mountain preserves are the largest open spaces of the city. South Mountain Park, with 16,500 acres, is the largest municipal park in the world and lies immediately south of the centre, separating the district of Ahwatukee from the rest of the city. The Phoenix Mountains Preserve protects the chain that includes Piestewa Peak, North Mountain and Sunnyslope Mountain, known locally as S Mountain for the letter laid out on its slope. The park system of the city as a whole contains 182 parks and more than 41,900 acres, the largest municipal system in the United States.

Hiking is the standard way into these mountains. Camelback Mountain offers two strenuous routes, the Echo Canyon Trail at 1.14 miles and the Cholla Trail at 1.4 miles, both climbing about 390 metres to the summit. Since 2024 the city has closed the trails between eight in the morning and five in the afternoon during periods of extreme heat, a reminder of how quickly the desert sun becomes dangerous. Shorter walks lead through the Desert Botanical Garden and along the interpretive trails of Papago Park, and the flat canal paths cross the valley for many kilometres.

Cycling and horse riding belong to the same system, and the canals that cross the valley have been converted in places into continuous routes that connect the suburbs with the centre. Maricopa County maintains the largest park system in the country, and Tonto National Forest forms part of the north eastern boundary of the city, so the desert is never far from the pavement. Golf and resort recreation complete the picture: the metropolitan area has more than 200 courses, most of them irrigated and green against the surrounding desert.

For the traveller the city works as a base as much as a destination. Sky Harbor Airport, among the ten busiest in the United States with about 45 million passengers a year, lies minutes from the centre, and from Phoenix the Grand Canyon, Sedona, the Petrified Forest, Meteor Crater, Lake Havasu and the Mexican border are all within a day’s drive. The Agua Fria National Monument, Montezuma Castle, Montezuma Well and the Casa Grande Ruins lie closer still, and the desert preserves begin at the end of the tram line.

The food of the valley belongs to the Sonoran Desert and to the border. Mexican cooking is everywhere, from taco counters and food trucks to long established family restaurants, and the kitchens of the Tohono O’odham and the Akimel O’odham use ingredients that grow in few other places in the same form: saguaro fruit, cholla buds, mesquite flour and tepary beans. The evenings grow lively as the heat leaves the streets, in the arts districts along Roosevelt Row and in the historic neighbourhoods where the older houses have deep porches and shade trees.

References

1. Wikipedia contributors (2026). Phoenix, Arizona. en.wikipedia.org/wiki/Phoenix%2C_Arizona
2. Wikipedia contributors (2026). Salt River Valley. en.wikipedia.org/wiki/Salt_River_Valley
3. Wikipedia contributors (2026). Sonoran Desert. en.wikipedia.org/wiki/Sonoran_Desert
4. Wikipedia contributors (2026). Hohokam. en.wikipedia.org/wiki/Hohokam
5. Wikipedia contributors (2026). Salt River (Arizona). en.wikipedia.org/wiki/Salt_River_%28Arizona%29
6. Wikipedia contributors (2026). Basin and Range Province. en.wikipedia.org/wiki/Basin_and_Range_Province
7. Wikipedia contributors (2026). Camelback Mountain. en.wikipedia.org/wiki/Camelback_Mountain
8. Wikipedia contributors (2026). Papago Park. en.wikipedia.org/wiki/Papago_Park
9. Wikipedia contributors (2026). Maricopa County, Arizona. en.wikipedia.org/wiki/Maricopa_County%2C_Arizona
10. Wikipedia contributors (2026). Arizona. en.wikipedia.org/wiki/Arizona
11. Wikipedia contributors (2026). Saguaro. en.wikipedia.org/wiki/Saguaro
12. Wikipedia contributors (2026). Desert Botanical Garden. en.wikipedia.org/wiki/Desert_Botanical_Garden
13. Wikipedia contributors (2026). Tempe, Arizona. en.wikipedia.org/wiki/Tempe%2C_Arizona
14. Wikipedia contributors (2026). Scottsdale, Arizona. en.wikipedia.org/wiki/Scottsdale%2C_Arizona
15. Woodbury R.B. (1960) The Hohokam Canals at Pueblo Grande, Arizona. American Antiquity. 26. 267-270. doi.org/10.2307/276206
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17. Drezner T.D. (2007) Variation in age and height of onset of reproduction in the saguaro cactus (Carnegiea gigantea) in the Sonoran Desert. Plant Ecology. 194. 223-229. doi.org/10.1007/s11258-007-9286-9
18. Krymkowski D.H., Manning R.E., Valliere W.A. (2014) Race, ethnicity, and visitation to national parks in the United States: Tests of the marginality, discrimination, and subculture hypotheses with national-level survey data. Journal of Outdoor Recreation and Tourism. 7-8. 35-43. doi.org/10.1016/j.jort.2014.09.008
19. Robison J. (2016) Climate Change and Allocation Institutions in the Colorado River Basin. Drought and Water Crises. 289-314. doi.org/10.1201/b19534-20