We were happy to leave Vegas. The character of this city did not match to the spirit of our expeditions. On the way to Arizona, we stopped to see the Hoover Dam. No doubt, it is impressive monument and quite popular among the tourists. After a short time, we were back on the road.

We spent the night near Catalina, AZ. In complete darkness, we hastily pitched a tent and quickly went to sleep. At night coyotes, who talked very loudly to each other, awakened us. When we got up in the morning, it turned out that all around us are hundreds of burrows in the ground. Our tent was set up in the area inhabited by small rodents called round-tailed ground squirrel. There were plenty of them. Exactly like prairie dogs, they build a colony of complex underground tunnels and burrows.

A large part of the day, we spent visiting the Biosphere 2, the research center, where in the 1990's the unusual experiment was conducted. A group of scientists locked and isolated from the outside world lived there for exactly two years. It was a time when the potential use of closed bases in the colonization of space was explored. After the completion of this experiment, the whole project collapsed. Today the building is part of the research related to climate change, human impact on the environment, etc.

In the early afternoon, we visited the ruins of Casa Grande in Coolidge, Arizona. These are the remains of the original buildings built hundreds of years ago by Pueblo Indians. There is not much to see, but after all, it was a nice break in our travel. Impressive, a few stories high building remains mysterious in many ways. The local peoples lived in villages similar to this, and watered their fields by digging a network of irrigation canals. There are possible ties to the civilizations of Mesoamerica.

In the evening, we arrived near Phoenix. It was time to get some rest.