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Arizona · 2018

2018 Arizona / California - Joshua Tree National Park

Endless sandy flatland dotted with scrub stretches beneath a cloudless sky.
Sun-baked ground with sparse shrubs and pale boulders fronts a rugged brown mountain range. A tall spiny ocotillo tipped with red blooms stands near a curving paved desert road. A cluster of bright red-orange flowers glows on spiny branches against deep blue. A silver sedan sits on the dirt shoulder of a highway through an empty desert plain. A craggy mountain range looms over sparse desert scrub beneath a clear blue sky. Clusters of fuzzy green cholla cacti blanket the desert floor below rocky hills. A large cholla cactus's golden spiny arms glow against the desert sky. Sunlit desert hills crowned with boulders and dotted with dry shrubs. A prickly cholla cactus shines golden in bright desert light. A spiky yucca stands in the foreground while a few vehicles wait on a rise. A branching Joshua tree rises above granite boulders on a desert slope. Two yucca plants lift dried seed heads high above the rocky desert. A jumble of rounded granite boulders sits behind green-crowned yucca plants. A single forked Joshua tree stands along the open desert floor. A weathered, twisted desert shrub tangles among huge boulders. Spiky Joshua trees lean on a sandy slope beneath a huge tan boulder. Crooked Joshua trees rise from sandy scrub beside pale desert boulders. Big smooth tan boulders stack into a rugged desert outcrop. One tall Joshua tree stands alone in a flat brushy desert field. A big branching Joshua tree towers over low plants in open desert. A gnarled Joshua tree frames a pale snow-capped mountain far off. From a rocky outcrop, dry hills fall to a hazy valley and distant mountains. Twisted Joshua branches frame a distant snow-dusted mountain peak. Knobby Joshua trees rise from sandy desert floor under bright blue sky. Joshua trees spread across a flat, brushy desert landscape. A sandy road curves through desert scrub past Joshua trees. A tall Joshua tree stands among agave plants and scattered desert shrubs. A wide desert valley stretches toward hazy mountains under a blue sky. An asphalt highway winds through desert toward a distant town and mountains. Rustic homes, palm trees and a camper sit on a rocky desert hillside. An aged desert shed stands alone behind a fenced compound. An empty straight highway cuts toward distant bare mountains. The desert highway reflection fills a car's side mirror. Towering saguaro cacti stand over a dry desert plain. A sandy track runs between saguaros beneath power lines. A broad dirt track crosses a cactus-studded desert. Saguaro cacti dot a wide, dusty desert plain. Looking down from desert scrub toward a hazy valley below. An elevated view shows a dense forest of saguaro cacti. Tall saguaro cacti stand among brushy desert plains beneath scrubby brown hills. Two large saguaro cacti rise in the foreground with an arid mountain range behind. A green saguaro trunk grows up through the branches of a sprawling desert tree. A broad prickly pear bush sits in front of a hillside dotted with cholla cacti. Saguaro cacti rise from dry grass and boulders below pale desert mountains. A small grey rabbit crouches in the shade of a dense tangle of dry branches. A cluster of spiny desert cacti is dotted with vivid pink blossoms on gravelly ground. A pale stony streambed winds through desert scrub toward rugged hills on the horizon. A dry desert wash scattered with scrub brush and saguaros stretches toward rugged mountains. A lone saguaro stands beside a winding desert path framed by a gnarled leafless tree. From a scrubby ridge, the view opens across a wide desert valley to distant blue mountains. A tight group of barrel cacti, tipped with rust-red spines, sits among desert stones. A brown Ford Canyon Trail sign marks the start of a path winding through a saguaro desert. A towering saguaro dominates the foreground while a branched one rises against scrubby desert hills. Cholla cacti dot the foreground of an open desert plain that falls away to a distant valley. A collapsed saguaro lies in pieces beside a weathered stump on an open desert floor. Cholla cacti cluster in the foreground beneath a tall saguaro on a rocky slope. Wide desert plain dotted with cholla bushes and a towering saguaro beneath a blue sky. Saguaro and shrubs dot the lower slopes of a jagged rock range. Gentle desert hills dotted with saguaros and rock outcroppings under a hazy sky. A dirt path winds through scrub toward a large mountain peak. A flat desert valley of saguaros and mesquite stretches to a distant mountain ridge. A scrubby hillside descends to a valley and a far mountain ridge. A tall saguaro stands in front of a slope dense with cacti and reddish rock. A small rock squirrel perches alertly on a gray boulder in a dry rocky desert. A rock squirrel peeks out from between lichen-covered desert boulders. Tall saguaro cacti rise above desert scrub with distant mountains beneath a blue sky. A dense group of saguaro cactus arms rises on a scrubby rocky slope.
Journal Notes

General

The desert journey began in Arizona and ended in California, and the two halves of it are two different deserts. The road out of Phoenix runs north and west through the Sonoran Desert, the warmest and wettest of the North American deserts, where the saguaros stand along the highway like columns, and it crosses the Colorado River into the Mojave, the higher and drier country that the Joshua trees belong to.

The drive is the point of the journey as much as the destination. The distances between the towns are long, the roads are straight, and the landscape changes slowly: first the cactus forest of the lower desert, then the open basins with their dry washes and scattered ranges, then the higher ground of the Mojave with its yucca and its granite. There is very little traffic and no shade at all, and the sky takes up most of the view.

The stay in Arizona was in the desert west of the city, where the White Tank Mountains rise out of the plain and a regional park protects the range and the country around it. The walking there is on the trails that climb out of the washes into the hills, and the plants along the way are the whole catalogue of the Sonoran Desert: saguaros of every size, cholla cacti with their golden spines, prickly pear, ocotillo with its red flowers at the tips, and the creosote bushes that give the air its smell after rain.

The second half of the journey was in California, in the national park that protects the transition between the two deserts. The approach from the east is through the town of Twentynine Palms, which is the main entrance to the park and a small place of motels, gas stations and desert yards, and the road into the park climbs from the flats into a landscape of boulders that is unlike anything the drive has prepared the visitor for.

The park itself is made of enormous piles of pale rock. The boulders are stacked in heaps and walls and rounded outcrops, the Joshua trees stand among them in ones and twos or in loose forests, and the roads loop between the formations for forty miles without ever leaving the rock. The light in the afternoon turns the stone the colour of honey, and the shadows in the hollows are as blue as the sky.

History

People have lived in these deserts for thousands of years, and the park records them. The earliest groups hunted game and gathered seasonal plants, and the later peoples of the region, the Serrano, the Cahuilla and the Chemehuevi, lived in small villages near the few sources of water, particularly at the Oasis of Mara in the place that the settlers later called Twentynine Palms. Their trails and their water sources are the oldest human geography of the country the visitor drives through.

The modern history of the desert begins with the mines. The Mojave holds silver, tungsten, iron and gold, and the discoveries of the nineteenth century brought prospectors, roads and small towns into country that had been crossed only by traders and the mail. The first recorded exploration of the Twentynine Palms area was made by Colonel Henry Washington, who found the Chemehuevi living in the hills near the spring that gives the place its name, and the town grew from a stage stop and a ranch into the gateway of the park.

The protection of the desert is a twentieth century story with two dates. The area was declared a national monument in 1936, which put the Joshua trees and the rock formations under federal management while leaving the country around them open to mining and ranching, and it was redesignated as a national park in 1994 under the California Desert Protection Act, which also set aside a large part of it as designated wilderness. The park is now one of the largest in the country and one of the most visited of the desert parks.

The water that made the modern cities possible came from far away. The Central Arizona Project, a canal of more than five hundred kilometres, diverts water from the Colorado River into the middle of the state, and the cities of the Salt River Valley have grown on it: Phoenix, the capital and the largest city of Arizona, has passed one and a half million residents and its metropolitan area more than five million, in a valley that receives a few inches of rain a year.

The last chapter of the story belongs to the visitors. The park is close enough to the cities of southern California to be a day trip, far enough to feel empty, and famous enough to draw climbers, walkers and drivers from all over the world. The town of Twentynine Palms has grown with them to a population of about twenty eight thousand, and the road that was built for the mines now carries the traffic of a national park and a marine base beyond it.

Geology

The two deserts of the journey are divided by height and by the weather. The Mojave is the higher of the two, mostly between six hundred and twelve hundred metres above the sea, and it lies in the rain shadow of the Sierra Nevada and the ranges of southern California, which take the water out of the air before it reaches the desert. The Sonoran Desert is lower and warmer, it receives rain from the Pacific in winter and from the monsoon in summer, and it is that second season of rain that allows the saguaro and the other giants of the Arizona desert to grow.

The park stands on the boundary between them. It covers parts of both deserts, the higher Mojave with its Joshua trees and the lower Colorado Desert with its creosote and its ocotillo, and the boundary is a matter of elevation rather than of lines on a map. The transition is visible on the drive from the north entrance to the south, where the vegetation changes within a few kilometres from the one desert to the other.

The rock of the park is the reason for its shape. It is mostly monzogranite, a coarse granite that was intruded into older rocks as a series of molten bodies during the age of the dinosaurs and then, after tens of millions of years of burial, was exposed by erosion and split by the cooling and the release of pressure into the rounded blocks that the visitor sees. The boulders are not carried there by rivers or glaciers; they are the bedrock itself, broken in place and smoothed by the weather.

The whole region is also a fault country. The San Andreas Fault runs through southern California for more than a thousand kilometres, it marks the boundary between the Pacific and North American plates, and it slips at an average of twenty to thirty five millimetres a year: the energy of that movement is what produced the mountains and the basins of the desert, and the fault itself passes close to the park and under the valley to the south, where the oasis of the region sits on the line of the water it brings to the surface.

The surface of the desert is the work of water that is hardly ever there. The storms of the winter and the summer arrive in short intense bursts, and the water that falls on the bare mountains arrives at the foot of them as a flood that spreads its load of sand and gravel into the fan shaped slopes along the edges of the valleys. The washes that cross the desert floor are the channels of those floods, dry for most of the year and dangerous for a few hours, and the alluvial fans that they have built are the ground on which the roads and the towns stand.

Things to See

The trees are the first thing to see and the reason for the park’s name. The Joshua tree is a yucca, not a tree in the ordinary sense, and it grows in the Mojave alone, mostly between four hundred and eighteen hundred metres above the sea. It can pass twelve metres in height over a life of centuries, its leaves are stiff spikes at the ends of the branches, and the name was given by the Mormon colonists who crossed the desert in the middle of the nineteenth century and thought that the raised arms of the plant looked like the prophet Joshua praying.

The cacti of the two deserts are the other botanical education of the trip. The cholla grows as a bush of golden spined segments that detach at a touch, the prickly pear spreads in flat pads, the barrel cactus is a ribbed cylinder with hooks for spines, and the ocotillo is not a cactus at all but a plant of the tea family that puts out leaves within days of rain and drops them again when the ground dries. The creosote bush that dominates the open ground is the oldest plant of the desert in the sense that counts: single individuals spread outward in rings for thousands of years.

The saguaro belongs to the Arizona half of the journey and is the emblem of it. It grows only in the Sonoran Desert, it can pass twelve metres in height, it is the state wildflower of Arizona, and its ribs and its central trunk hold the water of the summer rains against the heat of the summer. The blossom of the saguaro and the fruits that follow it feed the birds and the bats of the desert, and the dead trunks stand for decades as the wooden skeletons that stand along the washes of the lower desert.

The animals are harder to see and worth the patience. The desert tortoise lives seventy years or more, spends most of its life in a burrow against the heat, and comes out after the rain to feed; it is the state reptile of California and a protected species whose numbers have fallen with the growth of the desert towns. The bighorn sheep keeps to the rocky ranges, the rock squirrel is the busy animal of the boulders and the picnic areas, and the cottontail and the jackrabbit are the small residents of the scrub.

The rock formations of Joshua Tree are a destination in themselves. The most famous of them stand in the Wonderland of Rocks, a jumble of rounded walls and corridors in the middle of the park, and the climbing on them is among the best in the United States, with thousands of routes from the beginner to the extreme. The walker who does not climb can still spend a day moving between the piles, following the trails through the sandy hollows where the water collects and the trees grow.

The park has two more things that the visitor should plan for. The first is the distance: the roads through it are long, the services are few, and the drive from one end to the other takes the better part of a day, so the water and the fuel should be taken in the town before entering it. The second is the night. The desert sky away from the lights of the cities is one of the sights of the country, and the park, which is far enough from Los Angeles and Phoenix to keep it, is a place where the stars are the last exhibit of the day.

The practical advice for the journey as a whole is the advice of the desert. Travel with more water than the plan requires, fill the tank at every opportunity, keep to the roads and the marked trails, and remember that the distances on the map are desert distances. The best months are the spring and the autumn, when the temperature is bearable and the plants are flowering; the summer is dangerous in the middle of the day and the winter nights are cold. The visitor who comes in the right season and stops the car often enough will find that the desert of the imagination is smaller and stranger than the real one.

References

  1. Wikipedia contributors (2026). Joshua Tree National Park. en.wikipedia.org/wiki/Joshua%20Tree%20National%20Park
  2. Wikipedia contributors (2026). Mojave Desert. en.wikipedia.org/wiki/Mojave%20Desert
  3. Wikipedia contributors (2026). Sonoran Desert. en.wikipedia.org/wiki/Sonoran%20Desert
  4. Wikipedia contributors (2026). Saguaro. en.wikipedia.org/wiki/Saguaro
  5. Wikipedia contributors (2026). Yucca brevifolia. en.wikipedia.org/wiki/Yucca%20brevifolia
  6. Wikipedia contributors (2026). Cylindropuntia. en.wikipedia.org/wiki/Cylindropuntia
  7. Wikipedia contributors (2026). Fouquieria splendens. en.wikipedia.org/wiki/Fouquieria%20splendens
  8. Wikipedia contributors (2026). Larrea tridentata. en.wikipedia.org/wiki/Larrea%20tridentata
  9. Wikipedia contributors (2026). Desert tortoise. en.wikipedia.org/wiki/Desert%20tortoise
  10. Wikipedia contributors (2026). Bighorn sheep. en.wikipedia.org/wiki/Bighorn%20sheep
  11. Wikipedia contributors (2026). White Tank Mountain Regional Park. en.wikipedia.org/wiki/White%20Tank%20Mountain%20Regional%20Park
  12. Wikipedia contributors (2026). Phoenix, Arizona. en.wikipedia.org/wiki/Phoenix%2C%20Arizona
  13. Wikipedia contributors (2026). San Andreas Fault. en.wikipedia.org/wiki/San%20Andreas%20Fault
  14. Wikipedia contributors (2026). Twentynine Palms, California. en.wikipedia.org/wiki/Twentynine%20Palms%2C%20California
  15. Wikipedia contributors (2026). Joshua Tree, California. en.wikipedia.org/wiki/Joshua%20Tree%2C%20California
  16. Wikipedia contributors (2026). San Bernardino Mountains. en.wikipedia.org/wiki/San%20Bernardino%20Mountains
  17. Wikipedia contributors (2026). Central Arizona Project. en.wikipedia.org/wiki/Central%20Arizona%20Project
  18. Wikipedia contributors (2026). Otospermophilus variegatus. en.wikipedia.org/wiki/Otospermophilus%20variegatus
  19. Pierson E.A., Turner R.M. (1998) An 85-Year Study of Saguaro (Carnegiea gigantea) Demography. Ecology. 79. 2676. doi.org/10.2307/176509
  20. Berry K.H., Murphy R.W. (2019) Gopherus agassizii (Cooper 1861), Mojave Desert Tortoise, Agassiz’s Desert Tortoise. Chelonian Research Monographs. doi.org/10.3854/crm.5.109.agassizii.v1.2019
  21. Novoa A. (2015) Cylindropuntia fulgida (jumping cholla). CABI Compendium. doi.org/10.1079/cabicompendium.37715
  22. Killingbeck K.T. (2023) TWO DISTINCT GROWTH FORMS OF THE ICONIC DESERT SHRUB OCOTILLO (FOUQUIERIA SPLENDENS): TARANTULA AND V-FORM. Madroño. 70. doi.org/10.3120/0024-9637-70.1.16
  23. Harvey A.M., Wells S.G. (2003) Late Quaternary variations in alluvial fan sedimentologic and geomorphic processes, Soda Lake basin, eastern Mojave Desert, California. Paleoenvironments and paleohydrology of the Mojave and southern Great Basin deserts. doi.org/10.1130/0-8137-2368-x.207
  24. Rango J.J. (2005) Arthropod communities on creosote bush (Larrea tridentata) in desert patches of varying degrees of urbanization. Biodiversity and Conservation. 14. 2185-2206. doi.org/10.1007/s10531-004-4669-x