The Notre Dame Mountains are a portion of the Appalachian Mountains, extending from the Gaspé Peninsula of Quebec to the Green Mountains of Vermont. The range runs from northeast to southwest, forming the southern edge of the St. Lawrence River valley, and following the Canada–United States border between Quebec and Maine. The mou…The Notre Dame Mountains are a portion of the Appalachian Mountains, extending from the Gaspé Peninsula of Quebec to the Green Mountains of Vermont. The range runs from northeast to southwest, forming the southern edge of the St. Lawrence River valley, and following the Canada–United States border between Quebec and Maine. The mountainous New Brunswick "panhandle" is located in the Notre Dame range as well as the uppermost reaches of the Connecticut River valley in New Hampshire.