The Saint Lawrence River 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 of the Great Lakes Basin. It traverses the Canadian provinces of Quebec and Ontario and forms part of the international boundary between Ontario, Canada, and the U.S. state of New York.

The St. Lawrence Seaway is the common name for a system of canals that permits ocean-going vessels to travel from the Atlantic Ocean to the Great Lakes, as far as Lake Superior. Legally it extends from Montreal to Lake Erie, including the Welland Canal and the Great Lakes Waterway. The seaway is named after the Saint Lawrence River, which it follows from Lake Ontario to the Atlantic Ocean. - Wikipedia

The St. Lawrence River and Seaway is of vital geographic and economic importance to the Great Lakes system, connecting the lakes to the Atlantic Ocean and providing navigation to deep-draft ocean vessels. Approximately 800 miles (1,287 km) long, the St. Lawrence River can be divided into three broad sections: the freshwater river, which extends from Lake Ontario to just outside the city of Quebec; the St. Lawrence estuary, which extends from Quebec to Anticosti Island; and the Gulf of St. Lawrence, which leads into the Atlantic Ocean.

The St. Lawrence River drops 226 feet between Lake Ontario and Montreal, Canada. To allow vessels to pass through the river and in and out of the Great Lakes, the St. Lawrence Seaway, a massive American-Canadian navigational project, was begun in 1954 and completed in 1959. The Seaway created the final link in the Great Lakes-St. Lawrence River system, connecting Duluth, Minnesota, some 2,340 miles (3,766 km) away, with the head of the Gulf of St. Lawrence, through a complex system of lakes, rivers, deepened channels, locks, and canals. - Great Lakes Information Network

St Lawrence River, grand river and estuary, which together with the GREAT LAKES forms a hydrographic system that penetrates 3790 km into N America. The river proper, about 1197 km long, issues from Lake Ontario, flows NE past Montréal and Québec City to the Gulf of ST LAWRENCE, from about 44° N lat near Kingston to about 50° N lat near Sept-Iles.

The river's DRAINAGE BASIN covers some 1 million km2, of which 505 000 km2 is in the US, and its mean discharge of almost 10 100 m3/s is the largest in Canada. Its greatest tributary, the OTTAWA R, drains some 140 000 km2, the SAGUENAY R about 88 000 km2, the MANICOUAGAN R about 45 000 km2, the ST-MAURICE R some 43 300 km2 and the RICHELIEU R about 22 000 km2. In geological terms, the St Lawrence is a young river, whose bed is a deep gash in the Earth's crust exposed some 10 000 years ago as the glaciers receded. - Canadian Encyclopedia

Thousand Islands

The Thousand Islands is the name of an archipelago of islands that straddle the U.S.-Canada border in the Saint Lawrence River as it emerges from the northeast corner of Lake Ontario. They stretch for about 50 miles (80 km) downstream from Kingston, Ontario. The Canadian islands are in the province of Ontario. The U.S. islands are in the state of New York. The islands, which number 1,793 in all, range in size from over 40 square miles (100 km²) to smaller islands occupied by a single residence, to even smaller uninhabited outcroppings of rocks that are home to migratory waterfowl. The number of islands was determined using the criteria that any island must be above water level for 365 (366) days per year, bigger than one square foot (roughly 900 cm²), and support at least one living tree. The area is very popular among vacationers, campers, and boaters, and is often referred to as the "fresh water boating capital of the world".

The area is frequently traveled by large freighters traveling the St. Lawrence Seaway, but is so riddled with shoals and rocks that local navigators are hired to help the vessels travel through the hazardous waterway. Under the Canadian span, a vessel just less than 25 feet (7.6 m) offshore can find itself in over 200 feet (61 m) of water. Similarly, rocks and shoals less than two feet (61 cm) underwater can be found in the center of channels 90 feet (27 m) deep. Because of the great number of rocks and shoals just above or below the water's surface, it is unwise to travel the waters at night, unless one stays in the main channels and has charts, a chart plotter, or knows the area well. The water is so clear in some areas, that a rocky bottom can be observed in 80 feet (24 m) of water. The area features several shipwrecks and is a great place for diving. Although most of the wrecks are over 100 feet (30 m) underwater, some are a mere 15 feet below the water's surface and can be seen by looking overboard. - Wikipedia

Boldt Castle

Boldt Castle, located on Heart Island (New York) in the Thousand Islands of the St. Lawrence River, along the northern border of New York State, is a major landmark and tourist attraction in its region.

George Boldt, proprietor of the Waldorf-Astoria Hotel and the Bellevue-Stratford Hotel in New York City, and his family for several summers enjoyed an earlier frame cottage on Hart Island (the original name) which they greatly expanded. In 1900 the Boldts launched an ambitious construction campaign to build a huge masonry structure, one of the largest private homes in America. They engaged the architectural firm G. W. & W. D. Hewitt and hundreds of workers for a six-story "castle", a major international landmark. In addition four other masonry structures on the island are architecturally notable. Equally distinctive is a huge yacht house on a neighboring island where the Boldts had another summer home and a vast estate, incorporating farms, canals, a golf course, tennis courts, stables, and a polo field. - Wikipedia