On our way back to the Phoenix airport from Puerto Penasco, we visited the Pinacate Biosphere Reserve. It is only about 30 minutes from town right off the main highway. The Pinacate Reserve is a volcanic field of almost 800 square miles and is one of the largest landforms visible from space in North America. The land is very similar to the moon's surface and NASA sent astronauts to train there from 1965 to 1970.
After stopping at the visitor center and paying a nominal fee (about $5 each), we took our 2 wheel drive car around the 2½ hour self-paced driving tour to see the volcanic peaks, cinder cones, and Maar craters. A Maar crater looks like a meteor crash site, but it's formed when an eruption of lava hits the layer of groundwater causing an explosion and collapse of the top crust.
The one-way path was dry and dusty, but full of amazing contrasts. The black lava rock and desert flowers; the barren desert and volcanic cones popping out of the ground; the gorgeous orange rocks of the Cerro Colorado crater against the bright blue sky.
The Cerro Colorado is over a half mile high and so beautiful! You could see how the explosion took place and how the layers collapsed upon each other.
The starkness was obvious, but there was beauty everywhere. To see the desert in full bloom, try to visit in February and March after the spring rains. Be aware, though, that you might need a 4-wheel drive to travel the roads. Some areas get flooded, but we were told that the views are amazing!