http://www.theguardian.com/science/2...ats-study-says
Don't blame the rats, it was the great gerbil and climate change
This is also the origin of the saying "raining cats and dogs." Cats and dogs would sleep in the thatch, and when it rained so hard that the cats and dogs came down it was "raining cats and dogs."
Plague is found here almost every summer in prairie dog populations. They carry the fleas which are the vector for yersinia pestis, the bacteria that causes plague.
In most healthy adults plague is not a lethal disease; and if caught in time is usually treatable with common antibiotics. "Plague" sounds pretty scary but it is relatively common in dry western states. Not necessarily human cases, but animal cases.