I'd say it's either a northern pine or an anery corn snake; both are harmless.  We had an anery corn snake named Candycorn - lived to 7 and grew to 5.2 ft.
 
If you go outside and alarm the snake (wave a stick in its general vicinity).  If it starts shaking it's tail like a rattler and violently hisses at you - that's a northern pine trait.  If it does pretty much nothing...or slinks away, or acts curious in regard to the stick -  it's probably an anery corn.
 
I don't know anything about snakes other than my own experiences with Candy.   I'm sure others on the board will chime in to help you.