Granville Notch, or Granville Gulf, is a notch, or mountain pass, located in Granville, Vermont. North of the height of land, the notch is the source of the Mad River, which drains into the Winooski River, and into Lake Champlain.Lake Champlain drains into the Richelieu River in Quebec, thence into the Saint Lawrence River, and into the Gulf of Saint Lawrence.To the south, the notch is drained by Alder Meadow Brook, a tributary of the White River, which drains into the Connecticut River, and into Long Island Sound in Connecticut.