Top 10 Interesting Facts About Lake Ontario

Did you know that Canada’s most populous province was named for one of the 5 Great Lakes of North America?

In this post, we’ll take a closer look at some interesting facts about Lake Ontario, the easternmost of the wonderful lakes near the Canada-United States border.

1. It’s surrounded by 1 Canadian province and 1 US state

Lake Ontario is one of the Great Lakes of North America which means it’s situated near the Canada-US border. Better yet, the border between the two countries is situated exactly in the middle of the lake!

This means that the north, west, and southwest of the lake are part of the Canadian Province of Ontario (which was named for the lake). The south and east of the lake are part of the U.S. state of New York.

Because it’s the easternmost of the 5 Great Lakes, it’s the only one that doesn’t border the U.S. State of Michigan.

Lake Ontario in Canada
The lake in Canada / Pixabay

2. It’s the smallest of the 5 Great Lakes by surface area

Even though it’s the smallest of the 5 Great Lakes, Lake Ontario is still the 13th-largest lake in the world (when the Caspian Sea is included) with a surface area of 7,340 square miles (19,000 square kilometers).

That’s quite a bit smaller than the largest of the 5 Great Lakes, Lake Superior, which has a total surface area of 31,700 square miles (82,100 square kilometers).

The lake has a maximum length of 193 miles (311 kilometers) and maximum width of 53 miles (85 kilometers). With a maximum depth of 802 feet (244 meters) and an average depth of 283 feet (86 meters), it’s also deeper than Lake Erie.

This makes it the 4th-biggest of the 5 Great Lakes by volume as it holds 393 cubic miles (1,640 cubic kilometers).

Lake Ontario Sattelite
Satellite image of Lake Ontario / Wiki Commons

3. It has multiple inlets and one very famous one

Many big and smaller important rivers drain into the lake. These rivers include the Don River, Humber River, Trent River, Cataraqui River, Genesee River, Oswego River, Black River, Little Salmon River, and the Salmon River.

The most famous and important of all rivers is the Niagara River, famously known for some of the best-known waterfalls in the world, Niagara Falls.

This river only has a length of 36 miles (58 kilometers) and first drains Lake Erie while flowing north to Lake Ontario. The river is also important as a landmark because it forms the natural border between the Canadian province of Ontario and the U.S. State of New York.

Niagara falls near lake ontario
The Niagara Falls / Wiki Commons

4. It’s the final lake in the Great Lakes chain

As the easternmost lake of the 5 Great Lakes of North America, it’s the final lake in the so-called “Great Lakes Chain.” This means that all of the 5 Great lakes are interconnected with each other through rivers, canals, and locks.

Lake Ontario is the final lake before the Great Lakes Chain drains into the Atlantic Ocean. It does so through its main outlet, the Saint Lawrence River, which forms the eastern end of the Saint Lawrence Seaway.

This seaway allows oceangoing vessels to travel across all the 5 Great Lakes, all the way to Duluth, Minnesota, which is situated in the western part of Lake Superior.

The Saint Lawrence River has a total length of 310 miles (500 kilometers) (excluding its estuary) and flows through the cities of Montreal and Quebec City in Canada before releasing into the Atlantic Ocean.

saint lawrence river montreal
Saint Lawrence River in Montreal / Wiki Commons

5. It was once a bay of the Atlantic Ocean and it’s still tilting

The Saint Lawrence River wasn’t always the connection between the 5 Great Lakes and the Atlantic Ocean. At the end of the last Ice Age about 13,000 years ago, there was an ancient lake named “Glacial Lake Iroquois” which was much larger than Lake Ontario today.

The surface area of this ancient lake was situated about 100 feet (30 meters) above the surface area of the lake we know today. It also drained to the southeast near the city of Rome, New York.

When the ice started to melt, the surface area of the lake gradually lowered. One of the most amazing facts about Lake Ontario is that during this period, it temporarily became a bay of the Atlantic Ocean. The city of Montreal in Canada was located right in the middle of this bay.

Because of the melting ice following the last Ice Age, the land rebounded as the heavy ice disappeared. This rebounding motion is still ongoing, which means that the lake bed is slowly tilting southward right now at a pace of 12 inches (30 centimeters) per century.

saint lawrence river quebec
Aerial view of the Saint Lawrence River / Abdallah /

6. Its name was derived from a Huron word

The name Ontario was derived from the Huron word “Ontarí’io,” which literally translates to “great lake.” The lake played an important role in the life of indigenous people living in the area. This also means that the Canadian province was named for the lake and not the other way around.

The lake formed the natural border between the territory of the Huron People and the Iroquois Confederacy, a confederation of pre-Columbian people living on the shores of Lake Ontario.

Lake Ontario facts
Sunset at the lake / Wiki Commons

7. It was once named for the French King in the 17th century

The first Europeans to travel to the lake were the French in the early 17th century. The first man to reach the lake was a French explorer named Étienne Brûlé in 1615.

Brûlé, who was still in his early 20s during his first trips into what is now Canada, spent most of his life with the Huron People. He learned their language and became an interpreter in the area.

The story of his demise is that he betrayed them (or they assumed he did) and they stabbed him to death, followed by being barbecued and eaten by the villagers. This story isn’t a confirmed one, though.

The French who arrived in the area renamed the lake to “Lac de St. Louis,” which translates to “Lake St. Louis,” most probably a reference to King Louis XIV of France. It wasn’t until the 1660s that historians referred to it as “Lacus Ontarius” which became “Lake Ontario.”

who discovered lake ontario
View of the amazing lake / Wiki Commons

8. The biggest cities were built with stones from the lake bed

Following the explorations of the French in the 17th century, many initial trading posts and forts were established in the area by both the British and French. Some of these included Fort Frontenac in 1673, Fort Oswego in 1722, and Fort Rouillé in 1750.

The location of the lake as the closest to the Atlantic Ocean resulted in early settlements being built as well. The former capital of Canada, for example, Kingston, Ontario, probably dates back to the establishment of Fort Frontenac in 1673.

The real construction boom started following the War of 1812 as more and more canals were built on both sides of the lake. Major cities in the area started exploding such as Toronto in Canada and Rochester in the United States.

Most buildings in the late 19th and early 20th centuries were constructed with stones produced by an industry that completely disappeared called stone hooking. The stone hooker literally scraped the bottom of the lake to gather stones that could be used as construction materials.

These stones, referred to as “Dundas shale,” were replaced with Portland cement as a building material and the stone hooking industry vanished as a result.

Lake Ontario in toronto
The lake with Toronto in the background / Wiki Commons

9. The lake has frozen over completely on 5 different occasions

Yes, it can be freezingly cold near the shores of the lake in the winter! This also means that parts of the lake freeze over as the temperatures drop below zero.

An ice sheet covering the lake anywhere between 10 and 90% is common, and most of the shallower parts of the lake and bays completely freeze every winter.

Only 5 times has the lake completely frozen over in recorded history, and this happened in 1830, 1874, 1893, 1912, and 1934.

The lake also produces a “lake-snow effect,” which means that the cold winds that pass the lake pick up moisture and produce snow. Because these winds usually come from the northwest, the southern and southeastern parts of the lake are referred to as the “Snowbelt.”

Lake ontario frozen over
The lake when it’s frozen over / Lord of the Wings /

10. The Toronto Islands are popular tourist destinations

Toronto is an amazing city to visit and features numerous fascinating landmarks, including the CN Tower which can be seen from all around the area s its antenna spire towers 1,815.3 feet (553.3 meters) above the lake’s surface.

The island just near Toronto is called the “Toronto Islands” and is a popular tourist destination in the area as well. These 15 small islands feature several parks, the Centreville Amusement Park, and multiple popular beaches which are packed in the summertime!

Ferries bring tourists to the island and many visitors bring their bicycles to enjoy the amazing landscape of both the city of Toronto and Lake Ontario!

Toronto Island ferry
Toronto Island Ferry / Robert101 /