Definitely check out 'The Reach'. It has a sense of the supernatural that is really spooky, set against the backdrop of coastal Maine. 'The Raft' is also very good. The isolation of being on a raft in a Maine lake and the strange danger they face there makes for a great horror short story. These Maine - set stories by Stephen King are full of his signature horror elements.
For horror lovers, 'The Body' is a must - read. While it has elements of coming - of - age, it also has some dark and disturbing moments. Set in Maine, it gives that sense of a small - town world that can hold hidden terrors. Also, 'Uncle Otto's Truck' is quite scary. The concept of a possessed truck in the Maine countryside is both unique and horrifying.