Lying near the junction of the dry Sonoran desert and the even drier Colorado desert, Castle Dome, about a half-hour travel north of Yuma, is home to some tough plants and animals. One distinctive plant is the saguaro cactus, a seemingly universal symbol of southwestern deserts, although its range in the United States is actually restricted to only southern Arizona. Equally distinctive is the non-cactus ocotillo. The ocotillo consists of bony stalks that only occasionally grow small leaves when rainfall is sufficient. However, in the spring it produces pretty orange flowers on the top of the stalks.
The Castle Dome area looks inhospitable to animal life but there are some that thrive there. One of the most numerous is the small side-blotched lizard, of which I saw several during the collecting trip. A more impressive lizard is the chuckwalla, the second largest lizard in the United States that can grow well over a foot long. Primarily a vegetarian, this docile creature lurks near cracks or rock piles where it can hide when it feels threatened. Indeed I spotted a chuckwalla diving into one of the tailing piles near the Hull Mine when I was making a general search of the area. The picture below is of two specimens I discovered near the old mining town of Bagdad near Wickenburg.
My most interesting find was a southwestern speckled rattlesnake which was near a prospect in the Castle Dome Mine area in the late afternoon. Usually these rattlers are nocturnal but the April temperatures are cool enough for them to be out during the day. I didnít have my camera with me to photograph that one but below is a picture I took of a similar speckled rattlesnake in the Harcuvar Mountains further north. The subtle coloration shows that this species is adept at remaining hidden among the desert rocks. The last creatures I encountered was late at night while searching at the Hull Mine. I kept hearing a strange creaking noise that I figured must be sheet metal from the old mine structures swaying in the wind. Finally I realized that the sound was coming from a group of wild donkeys that seemed to be quarrelling among themselves.
Southwestern Speckled Rattlesnake