# The Great Lakes of Canada — All Five Explained
The Great Lakes are five massive freshwater lakes along the border between Ontario and the United States. Together they hold about 21% of the world's surface fresh water — a staggering amount. Here is what you need to know for the citizenship test.
The five Great Lakes
Use the mnemonic HOMES to remember them:
| Lake | Shared with US? | Surface area | Key fact |
|---|---|---|---|
| Huron | Yes | 59,600 km² | Second-largest; Georgian Bay is on its Ontario side |
| Ontario | Yes | 19,000 km² | Smallest by area; Toronto sits on its shore |
| Michigan | No (US only) | 57,800 km² | Only Great Lake entirely within the United States |
| Erie | Yes | 25,700 km² | Shallowest; connects to Ontario via Niagara Falls |
| Superior | Yes | 82,100 km² | Largest freshwater lake by area in the world |
Why they matter
The Great Lakes are important for several reasons:
Fresh water
They contain about 21% of the world's surface fresh water — enough to cover the entire landmass of North America in about 1.5 metres of water. Millions of Canadians and Americans depend on them for drinking water.
Shipping
The Great Lakes are connected to the Atlantic Ocean via the St. Lawrence Seaway — a system of locks and canals. Ocean-going ships can travel from the Atlantic all the way to the heart of the continent (Thunder Bay, Duluth, Chicago). This shipping route is vital for Canadian grain, iron ore, and manufactured goods.
Cities
Major cities sit on the Great Lakes:
- Toronto — on Lake Ontario
- Hamilton — on Lake Ontario (western end)
- Thunder Bay — on Lake Superior
- On the American side: Chicago (Michigan), Detroit (Erie/Huron), Cleveland (Erie), Buffalo (Erie)
Niagara Falls
Niagara Falls — one of the most famous waterfalls in the world — connects Lake Erie to Lake Ontario. The falls are on the border between Ontario and New York State. About 750,000 litres of water flow over the falls every second.
The St. Lawrence Seaway
The St. Lawrence Seaway is a system of locks, canals, and channels that allows ships to travel from the Atlantic Ocean to the Great Lakes — a distance of about 3,700 km. Opened in 1959, it was one of the largest engineering projects in Canadian history.
The St. Lawrence River itself connects Lake Ontario to the Gulf of St. Lawrence and the Atlantic. It was the main route into the interior of North America for early European explorers.
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The Great Lakes and Canadian history
The Great Lakes have been central to Canadian history:
- Indigenous peoples — the Haudenosaunee (Iroquois), Anishinaabe (Ojibwe), and Huron-Wendat peoples lived around the lakes for thousands of years
- French exploration — Samuel de Champlain explored the Great Lakes in the early 1600s
- Fur trade — the lakes were highways for the fur trade, connecting Montreal to the western interior
- War of 1812 — several key battles were fought on or near the Great Lakes
- Confederation — Ontario, the province most connected to the lakes, was one of the four original provinces in 1867
What the test asks
Common citizenship-test questions:
- Name the Great Lakes *(HOMES — Huron, Ontario, Michigan, Erie, Superior)*
- Which Great Lake is entirely in the United States? *(Michigan)*
- Which is the largest? *(Superior)*
For more on geography, see [The Five Regions of Canada](/blog/five-regions-canada-explained) and [The Three Oceans That Border Canada](/blog/three-oceans-border-canada).
Practice the actual citizenship test
Try our [free practice test](/practice-test) — it covers Great Lakes questions in the same format you will see on test day.
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Frequently Asked Questions
1What are the five Great Lakes?
Superior, Michigan, Huron, Erie, and Ontario. Remember: HOMES (Huron, Ontario, Michigan, Erie, Superior).
2Which Great Lake is entirely in the United States?
Lake Michigan. The other four — Superior, Huron, Erie, and Ontario — are shared between Canada and the US.
3Which is the largest Great Lake?
Lake Superior — it is the largest freshwater lake by surface area in the world (82,100 km²). Lake Huron is second-largest.
4Why are the Great Lakes important?
They hold about 21% of the world's surface fresh water, support major cities (Toronto, Hamilton, Chicago, Detroit), provide drinking water for millions, and are connected to the Atlantic via the St. Lawrence Seaway — a major shipping route.
5Is this on the citizenship test?
The Great Lakes can appear in geography questions — knowing their names (use HOMES) and that they form the Ontario–US border is helpful.