Tuesday, 5 October: Acoma Pueblo, New Mexico

Today we went to the Acoma (say ack-umma) Pueblo, about an hour's drive from our hotel in Albuquerque. The Acoma people are an ancient race of American Indians. The pueblo, or village, was built on the top of a 112 metre (367 foot) sandstone mesa. It is also called 'Sky City'. It is thought that the pueblo was built in the 12th century, but before that the people lived on another mesa, probably dating back to around the 7th century. No one knows why they moved, or why they built their village on top of a high, almost unreachable mesa. Possibly it was for defence.  However, in 1598, the Spanish invaded New Mexico, and raided many pueblos, including Acoma, taking anything of value. There were about 2000 people living in the pueblo when the Spanish conquered it, and only about 250 after the battle was lost.

The Spanish built a church on the mesa and the Indians were forced to become Catholics and to learn to speak and read Spanish. They found quiet ways of seeming to obey, while continuingtheir own ways in secret defiance.

Rainwater collects in rock depressions

Today there are still Acoma people living in the pueblo, though most now live in the surrounding plateau, making it one of the oldest continuously inhabited pueblos. Everything had to be carted up to the mesa, dragged on sleds pulled by mules. The Acoma people hunted the mostly small animals around, such as rabbits and snakes, and the occasional elk. They collected berries and nuts, and also planted small crops of corn and squash where they could. There are depressions in the rocks where rain water collects in large pools, which supplied the Acoma people with water. They collected what they needed in large pottery bowls and urns. Today the pools are used only for washing, and the residents cart drinking water up to the mesa. They have no electricity up there, and large gas cylinders supply gas for cooking. There are porta loos tucked away in unobtrusive locations, and a few four wheel drive cars are parked outside some houses. Clay dome-shaped wood ovens are dotted about for communal use, and bread is still baked daily. Most of the residents are artists, making traditional pottery, jewellery and ornaments for sale to visitors.

The Acoma people have built a visitor centre and small buses shuttle visitors up to the pueblo, where an Acoma guide takes them through the village. A licence to take photos must be obtained, and there are places where photographs cannot be taken.

Saturday, 16 October:Joshua Tree National Park

Joshua trees are a kind of yucca (say you-cuh) plant. They are desert plants, but occur at high altitudes. They were named by Mormon pioneers who were travelling northwards looking for a place where they could establish settlements and follow their religion in peace. When they saw the strange shapes of these trees they were reminded of a bible story about Joshua who raised his arms to the heavens to pray.

In this national park there are two kinds of desert. In the lower parts there is Colorado type desert: low tussocks of grass and low shrubs. As it gets higher, this kind of desert merges with yucca desert which takes over: small plants, yuccas and joshua trees. We started with Colorado type desert, and the rocks looked like piles of rubble. These gave way to huge boulders piled up.

At a place called Keys Point there was an overview of the Santa Rosa and San Jacinto mountains, and we could see the San Andreas fault, even though there was quite heavy haze in the distance.  The San Andreas Fault is a line of weakness in the earth's crust that runs through much of California.

As we descended to leave the park, the Joshua trees stopped abruptly and the Colorado type desert reappeared, this time with a cactus called cholla (say choy-ya), attractive but not to be touched. The silvery bristles that look fluffy are each tipped with a minute prickle. If you touch the plant or even brush against it as you walk past, the spines spear your clothing, shoes or skin. They hang on tight and a whole section of the plant comes off and stays with you. When it finally drops to the ground, it easily grows into new plants, which gives the cholla its nickname 'jumping cholla'.

We drove onto San Diego, our last destination.

Friday, 15 October: Salton Sea, California

Salton Sea is a huge inland rift lake about an hour's drive from Palm Springs. It is located on the San Andreas Fault, and is fed by three rivers. Its surface lies 69 metres below sea level, and its maximum depth is 16 metres. However, it has no water flowing out, only in. This has resulted in the lake becoming very salty. In fact, with 44 grams of salt to each litre of water, it is saltier than the Pacific Ocean. Since the 60s the salt level has risen sharply. In addition, fertiliser run off from nearby farms has led to blooms of algae.

There are ruins of holiday houses and caravans abandoned by people who decided not to keep holidaying on the lake. Many fish species have died out, unable to survive the rising salinity of the water. However, many bird species inhabit or use the lake as they migrate: about 400 different kinds of birds have been seen at Salton Sea.

In 1998 the Sonny Bono Salton Sea Restoration Project was launched, and is investigating ways to save the lake by reducing salt levels and bringing the lake and surrounds back to life. There are now some small settlements of new houses in places near the shore.

Wednesday, 14 October: Palm Springs, California aerial tramway

A cable car going up the mountain past one coming down

It is unseasonably hot in Palm Springs at the moment: around 36 - 38º C (96-102ºF).  We went on the aerial tramway, which is a cable car that goes up to Mt Jacinto State Park, 2596 metres (8516 feet) above sea level. The cars take about 80 people at once on the trip up, about 10-15 minutes. The cabin is round, and the floor slowly revolves so you look out of different windows as the trip progresses. Once at the top, there are restaurants and walking trails. The view is spectacular, looking out over Palm Springs, Las Palmas and the Coachella Valley. The state park is, apart from the tramway buildings, untouched wilderness, a habitat for many birds, such as the Golden eagle and yellow-headed woodpecker, and animals such as squirrels, coyotes, mountain lions and black-tailed deer. There are streams flowing down the mountainside, and you can track them by the green plants between the rocks. You can stay at the top for as long as you like, and catch a cable car down when it is convenient, as they run every 15 minutes. The trip down is better because there are just a few on board, and the view is therefore easier to see.

In the afternoon we took a jeep tour around the town, and learned a lot about its origins.  The Agua Caliente Indian Reservation adjoins and overlaps what is now the town of Palm Springs, and for hundreds of years the Cahuilla Indians used the hot springs that are in the location, regarding them as magical because soaking in the water cured so many aches. Gradually other people came to the springs, paying the Cahuilla for the experience. In time, a hotel was built, and movie stars and directors in the early days of Hollywood, the 1930s and 40s, began to build holiday homes there. Their contracts with the movie studios said they must not go further from Los Angeles than 100 miles... and Palm Springs is 99 miles away, another thing in its favour! The town grew from those origins. Today Agua Caliente is one of the richest of all the Native American tribes, and the town flourishes. The charming town retains its village atmosphere, with a strict building code limiting the height of buildings in the area.

A vast forest of wind turbines outside the town supplies all its energy needs.

Tuesday,12 October: The Grand Canyon Skywalk

Erosion by the Colorado River helped create the Grand Canyon

The Grand Canyon is situated entirely in Arizona. It is listed as one of the Seven Wonders of the World. Find out about it on http://kidcyber.com.au/topics/wonderlists.htm

The Skywalk opened in March 2007. It is a glass walkway that juts out over the edge of the Canyon on its western rim. It is 4000 feet or about 1400 m above the floor of the Canyon!

Skywalk juts out over the Canyon rim

Skywalk is owned by the Hualapai tribe of American Indians. Their Reservation of about 1 million square feet takes in the western rim, and they own about one third of the Grand Canyon. Engineers checked the western rim and chose the location. Huge steel beams were sunk about 46 metres into the rock. The large, massively thick glass plates that make up the floor were made in Belgium. When all the sections were complete and had been delivered up the mountain to the top of the Canyon, it took just a few days to complete the structure. The buildings around Skywalk are still being finished, and much more is planned, such as restaurants and hotels. Visitors buy a ticket, and are taken by shuttle bus, a ride of just 5 minutes or so, to Eagle Point. Only 120 people at a time are allowed onto Skywalk, and each is given cloth slippers to put over their shoes just before they walk out there to protect the glass from being scratched. There are glass walls around the walk, high enough to protect people from high winds.  To protect the glass floor, people are not allowed to take cameras or cell phones onto Skywalk. To get to the admission point, people can go by small plane or helicopter from Las Vegas or Kingman, or can drive from Kingman. However, the last 32 km (20 miles) before you enter Hualapai land is unmade road-and it is the only road in!

It is quite scary walking on the glass floor, even though you know that it is designed to withstand an earthquake of up to 9 on the Richter scale, and could support the weight of 11 or so fully fuelled and loaded jumbo jets! To step onto a floor through which you can see rocks 4000 feet below is strange, and there were some people who became quite anxious, especially when others jumped up and down!

Monday,11 October: Sedona, Arizona

We didn't realise that Sedona isn't heavily visited during the summer, but the autumn is peak season. We were unable to get accommodation here: everywhere has been booked out for months. So we contented ourselves with a delightful day trip. It is not a long drive from Flagstaff, and the narrow road cuts through mountain forests of Ponderosa pines and steep mountain passes. Suddenly the rocks become a deep red, and you are in Red Rock valley where Sedona is located. The scenery is just gorgeous wherever you look. The town itself is delightful, full of interesting art galleries, nice open air eating places and places offering fortune telling, psychic and tarot readings, or day spa treatments. It was a fascinating, fun day. This is definitely a place to return to, but next time perhaps not in its busiest time when it is crowded with tourists.

Sunday, 10 October: Meteor crater, near Flagstaff, Arizona

About 50,000 years ago a huge meteor smashed into the vast, flat plain near what is now the city of Flagstaff. It is estimated that it took 10 seconds for the fast-moving meteor to enter Earth's atmosphere and crash. Travelling at about 43,500 km per hour (27,000 miles per hour), or 18 kms (11 miles)  per second, it crashed with what would have been a huge flash. The meteor would have been about 56 metres or 150 feet wide, and would have struck with a blast greater than a bomb of more than 20 million tons of explosive. Shockwaves would have radiated out across the plain for several miles. The meteor would have broken into pieces, and small fragments would have melted and then hardened into tiny balls which are buried in the soil.

On right, there are people standing on a viewing platform

The result was a giant hole in the ground, 214 metres (700 feet) deep and more than 1220 metres (4000 feet) across. Over 170 million tons of rock were thrown out to form a blanket of rubble onto and around the rim.

NASA astronauts were trained for missions to the moon and Mars in the crater, and vehicles for use on the surfaces of the moon and Mars are tested there.