We have Eastern Timber Rattlers in NH, but they are reclusive and in the woods. Even hiking, if you keep to the trail and don't go out of your way to find them, you won't likely see any. They will "feel" you coming and disappear long before you know they're there.
In our yard (under the shed) we have Garter snakes, and sometimes Ribbon snakes (they look quite similar). Our climate is just too dang cold to support a large population of poisonous snakes!
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ETA: once some years ago DH and I were visiting Orton Plantation over near Southport, NC. We were walking along the brick walkway and suddenly came upon the biggest corn snake I'd ever seen!! It had to be near 4-feet long. And of course they blend perfectly with brick, so we didn't see it until we were right on it. It was along the edge of the walk, sunning itself. Real pretty snake, though.
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