Complex sentence: The region includes most of the state of New York, excluding New York City and its environs, as well as Long Island, the precise boundary is generally accepted as north of Sullivan, Ulster, and Dutchess counties.
Split into simpler sentences: The region includes most of the state of New York, excluding New York City and its environs, as well as Long Island. The precise boundary is generally accepted as north of Sullivan, Ulster, and Dutchess counties.