Maybe a Timber Rattlesnake
Carole,
On Saturday I came across a snake while walking in some rocky woods in N. Chelmsford, MA. I looked in a book when I got home and I am 99% certain that it was a Timber Rattlesnake. The only other snake in the book that looked similar was the Milk Snake, like in your picture. The Milk Snake in your picture has a distinctive marking like a white "Y" on the back of the head or neck that the Timber Rattlesnake doesn't have. When I peered closer it immediately snapped into a coil and let's just say I kind of jumped back!
from National Audubon Society Field Guide to New England:
TIMBER RATTLESNAKE
PIT VIPER FAMILY
3' 9". Body thick. Head thick, triangular. Tail has silvery rattle. Dark phase has black head, dark gray body, black blotches edged in white, black tail. Pale phase yellowish brown, with dark brown blotches, black tail. CAUTION Poisonous; coils before striking. Retreat from rattled warning. HABITAT Wooded hills with rocky outcrops. RANGE From s NH and Lake Champlain south, and east to Blue Hills of e MA (very local).