Northeast, yet they retain much of the early merchant trading and whaling culture. Cape Cod in particular is a popular retirement area; 31.8% of the population of Barnstable County is 65 years old or older., and the average age of residents is the highest of any area in New England. Cape Cod is majority Democrat, but by a smaller margin than the rest of Massachusetts. The bulk of the land in the area is glacial terminal moraine and represents the southernmost extent of glacial coverage in southeast New England; similar glacial formations make up Long Island in New York and Block Island in Rhode Island. Geography and political divisions Physical geography and boundaries The name "Cape Cod", as it was first used in 1602, applied only to the very tip of the peninsula. It remained that way for 125 years, until the "Precinct of Cape Cod" was incorporated as the Town of Provincetown. No longer in "official" use over the ensuing decades, the name came to mean all of the land east of the Manomet and Scusset rivers – essentially along the line that became the Cape Cod Canal. The creation of the canal separated the majority of the peninsula from the mainland. Most agencies, including the Cape Cod Commission and the Federal Emergency Management Agency (FEMA), treat the Cape as an island with regard to disaster preparedness, groundwater management, and the like. Cape Codders tend to refer to the land on the mainland side of the canal as "off-Cape", though the legal delineation of Cape Cod, coincident to the boundaries of Barnstable County, includes portions of the towns of Bourne and Sandwich that are located north of the canal. Cape Cod Bay lies in between Cape Cod and the mainland – bounded on the north by a line between Provincetown and Marshfield. North of Cape Cod Bay (and Provincetown) is Massachusetts Bay, which contains the Stellwagen Bank National Marine Sanctuary, located north of Provincetown. Cape Cod Bay and Massachusetts Bay are both part of the Gulf of Maine, which includes the waters between the Cape and Nova Scotia. The Atlantic Ocean is to the east of Cape Cod, and to the southwest of the Cape is Buzzards Bay. The Cape Cod Canal, completed in 1916, connects Buzzards Bay to Cape Cod Bay; its creation shortened the trade route between New York and Boston by . Cape Cod extends into