Saddleback Mountain stands within the watershed of the East Branch of the Ausable River, which drains into Lake Champlain, thence into Canada's Richelieu River, the Saint Lawrence River, and into the Gulf of Saint Lawrence.The southeast end and southwest side of Saddleback Mtn. drain into Shanty Brook, thence into the East Branch of the Ausable River between Upper and Lower Ausable Lake.The northwest end of Saddleback Mtn. drains into Chicken Coop Brook, thence into Johns Brook and the East Branch.The northeast side of Saddleback Mtn. drains into Ore Bed Brook, thence into Johns Brook.