You don't have to go to the desert to find a rattlesnake in the US. I don't know for sure about other areas but they are all over the South. Also the Cottonmouth Water Moccasin:
This dangerous semi-aquatic snake is truly an aggressive reptile that will stand its ground or even approach an intruder.
The Coral Snake:
The snake is classed with several Old World species like the neurotoxic cobras, kraits, and mambas.
Typically very small by comparison, averaging only 20 inches or so, this snake is seldom seen and tends to be very nocturnal. The snake spends much of its life underground in cracks and crevices.
Which is very easy to confuse with the benign Scarlet King Snake:
Remember the old saying: "red and yellow will kill a fellow." What this means is that RED AND YELLOW ARE NOT SEPARATED - the red and yellow bands touch. The California Mountain King Snake has a black head but does not have red and yellow bands that touch.