Does the Cottonmouth watermoccisin have a twin?

Question

I was in the yard this morning and spotted an all glossy black snake about 48 inchs long, I saw the white line on the mouth, it was not defined as I thought it would be, when I approached it it did not move, I've done some research, I am in southeast Kansas, the yard has several overgrown ponds, I fear for my 55 lb dog who is not woods wise and very curious as to these type things.Is this fear justified?

Answer 1

Cottonmouths typically open their mouths at you when they are mad, and also they tend to be a very thick looking snake. From your description, I might guess Eastern Racer. I have never seen a cottonmouth 48 inches long. Here is a list of snakes of Kansas, you might be able to figure it out by searching for pictures of these:

http://www.gpnc.org/reptiles.htm

Answer 2

Yes, it could be a cottonmouth. Without a picture it's impossible to identify. When provoked/cornered, they open their mouths--which are bright white on the inside--you'll know right away if it's a cottonmouth. The bites are not often deadly, but incredibly painful and prone to gangrene and resulting digit/limb loss.