Complex sentence: Peconic County is a proposed new county in New York to be formed out of the eastern part of what is now Suffolk County and would tentatively include the towns of East Hampton, Riverhead, Shelter Island, Southampton and Southold.
Split into simpler sentences: Peconic County is a proposed new county in New York. If created, it would consist of the easternmost portions of Suffolk County and would tentatively include the towns of East Hampton, Riverhead, Shelter Island, Southampton and Southold.