Route 138 is a major highway in the Canadian

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 province of Quebec

Quebec

Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

, following the entire north shore of the Saint Lawrence River

Saint Lawrence River

The Saint Lawrence is a large river flowing approximately from southwest to northeast in the middle latitudes of North America, connecting the Great Lakes with the Atlantic Ocean. It is the primary drainage conveyor of the Great Lakes Basin...

 past Montreal to the eastern terminus in Natashquan on the Gulf of Saint Lawrence

Gulf of Saint Lawrence

The Gulf of Saint Lawrence , the world's largest estuary, is the outlet of North America's Great Lakes via the Saint Lawrence River into the Atlantic Ocean...

. The western terminus is in Elgin

Elgin, Quebec

-About Elgin:Elgin is a rural municipality of less than 500 people in Quebec, Canada. The population as of the Canada 2006 Census was 458. It is located southwest of Huntingdon and bounded by the Trout and Chateauguay rivers and the Québec - US border...

, at the border with New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 State south-west of Montreal

Montreal

Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...

 (connecting with New York State Route 30

New York State Route 30

New York State Route 30 is a state highway in the central part of New York in the United States. It extends for from an interchange with NY 17 in the Southern Tier to the Canadian border in the state's North Country, where it continues into Quebec as Route 138. On a regional level,...

). Part of this highway is known as the Chemin du Roy

Chemin du Roy

The Chemin du Roy is a historic road along the north shore of the St. Lawrence River in Quebec. The road begins in Repentigny and extends almost eastward towards Quebec City, its eastern terminus...

, or King's Highway, which is one of the oldest highways in Canada.

It passes through the Montérégie

Montérégie

Montérégie is an administrative region in southwest Québec. It includes the cities of Boucherville, Brossard, Granby, Longueuil, Salaberry-de-Valleyfield, Saint-Jean-sur-Richelieu, Saint-Hyacinthe, Sorel-Tracy, and Vaudreuil-Dorion....

, Lanaudière

Lanaudière

Lanaudière is one of the seventeen administrative regions of Quebec, Canada, situated immediately to the northeast of Montreal. It has a total population of 429,053 inhabitants.-Geography:...

, Mauricie

Mauricie

Mauricie is a traditional and current administrative region of Quebec. La Mauricie National Park is contained within the region, making it a prime tourist location. The region has a land area of 35,855.22 km² and a 2006 census population of 258,928 residents...

, Capitale-Nationale

Capitale-Nationale

Capitale-Nationale is one of 17 administrative regions of Quebec, Canada. Quebec City, Quebec's centre of government, is located in this region. It has a land area of 18,638.7 km2...

 and Côte-Nord

Côte-Nord

Côte-Nord is the second largest administrative region by land area in Quebec, Canada, after Nord-du-Québec...

 regions of Quebec.