Mount Roosevelt stands within the watersheds of Lake Champlain and the Connecticut River. The southeast side of Mount Roosevelt drains into the Clark Brook, thence into the White River, the Connecticut River, and ultimately into Long Island Sound in Connecticut. The north and west sides of Mount Roosevelt drain into the headwaters of the New Haven River, thence into Otter Creek, Lake Champlain, Canada's Richelieu River, the Saint Lawrence River, and ultimately into the Gulf of Saint Lawrence.