Plesis is located in Jefferson County, New York. It is a tiny hamlet near the city of Alexandria. Plessis is known as a vacation area. It is located on the St. Lawrence River, and contains may of the Thousand Islands. Much of the business in the area focuses on boating and fishing on the many lakes and waterways. Local businesses include Swan Bay Estates & Marina and Thousand Island Bait Store. The Plessis area was first settled in 1811. The Battle of Cranberry Creek, during the War of 1812, took place nearby. Wellesley Hotel is a home away from home for many travellers to the area. Located near Plessis are Keewaydin State Park and Kring Point State Park, great places for camping, hiking and fishing.