Please help me determine what this is?

[ENCOC]

Hello all. We found this snake along our fence line yesterday. It is dark olive color with black spots. It is about 4 1/2 to 5 ft long. Thought it was a moccasin of some type but the more I look through images on the web I keep coming back to an anaconda or constrictor type. I know they are not native here by any means but wondering if it was someone's pet that got loose? I know I could be way off point being that I know nothing about snakes.

It was found in Eastern North Carolina.

Any idea what it is?

Thanks in advance for your help.