Snakes near the Shellpot Creek and in the garden!

I now need to be slightly more careful blundering around the flower beds. This large but seemingly harmless snake was hiding in the shade under some hostas two days ago. I tried to get in and get a better closeup but he slithered away under more cover and I was unable to hold camera and stick at the same time. This snake is considerably large than the garter snakes that we have seen around other parts of the yard, and I think it is larger than the ones we have seen swimming in the creek. I estimate two feet in length and twice as large than a garden hose around.

It was the snakes swimming in the creek that caused me to do some more research into what snakes are native to Delaware. I was particularly interested in any venomous snakes that are in Delaware since it is obvious that I will be encountering snakes as the days go by. Wikipedia has a nice list of snakes of New Jersey, which should be relevant, having the same climate though it is across the river. I think that list was put together with ease because it is based on the NJ Division of Fish and Wildlife Online Field Guide for Reptiles and Amphibians . There is no such list for Delaware that I have found in my searching yet. There is a long list of unstartedwikipedia articles for lists of snakes of each state. This caused me to find and buy an old article "List of Snakes of the United States and Canada by States and Provinces", by A.H.Wright and A.A. Wright, The American Midland Naturalist, Vol. 48, No. 3, PP. 574-603, Nov 1952.

I may be inspired to start the list for the Delaware wikipedia article, but I am not done searching for sources yet. As for venomous snakes in Delaware, I recognize Agkistrodon m. mokeson which is a copperhead as the only poisonous snake in Delaware. I will need to do more research to find out what the snake above is. Are there any herpetologists out there who can help?

Update (4-16-2010): Finally wanted to put in here that "Amphibians and Reptiles of Delmarva" by James White and Amy White helped me identify this snake as a Northern Water Snake, Nerodia sipedon sipedon. I probably new this not long after this original post, but I want it here for reference.