Mount Wilson stands within the watersheds of Lake Champlain and the Connecticut River. The southeast side of Mount Wilson drains into the headwaters of the White River, thence into the Connecticut River, which drains into Long Island Sound in Connecticut. The northeast side of Mount Wilson drains into the Clark Brook and thence into the White River. The northwest side of Mount Wilson drains 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.