Lake America Name Change Deepens US-Canada Rift

Donald Trump has turned his growing dispute with Canada into a battle over the name of a shared Great Lake.

On Thursday, Trump signed an executive order instructing the US federal government to use the name Lake America for Lake Ontario. The order covers the lake bordered by New York and the Canadian province of Ontario, making Lake America the official designation for federal use in the United States.

Trump said the change took effect immediately. However, the written order gives the Interior Department 30 days to complete the required administrative changes. Interior Secretary Doug Burgum must work with the US Board on Geographic Names to update the Geographic Names Information System. The order also directs federal agencies to replace Lake Ontario with Lake America on maps, contracts, documents and official communications.

The move does not mean the US can decide what Canada calls the lake. The US Geological Survey says the Board on Geographic Names standardises geographical names for the federal government. In Canada, the Ontario Geographic Names Board has the legal authority to recommend names for use on provincial government maps, publications and documents.

As a result, Lake America can become the US federal name while Canadian authorities continue to use Lake Ontario.

Private mapping companies are also not automatically required to follow the American order. US Geological Survey guidance says the federal government does not control the names used by outside organisations on non-federal maps. However, commercial companies have adopted federal changes before. After Trump ordered the Gulf of Mexico to be renamed the “Gulf of America” in 2025, the USGS said the new name also appeared on commercial platforms, including Google Maps and Apple Maps.

The Lake America decision comes amid a much wider economic dispute between Washington and Ottawa. According to the Associated Press, Trump described Canada as “the worst” to deal with on trade. He added: “They feel entitled, and we can’t have that,” AP reported. The news agency also said Trump had discussed changing the lake’s name after trade talks between the two countries broke down.

The tariff dispute has far greater financial consequences than the naming row. Canada’s Department of Finance said new 50 per cent US tariffs came into force on 22 August on Canadian goods worth C$27.6 billion. Ottawa responded with countermeasures covering the same value of American imports. A separate Canadian tariff schedule says those measures will begin on 8 September, with rates of 15, 25 and 50 per cent, depending on the goods involved.

Despite the political tensions, the two countries remain closely tied through trade. The Office of the US Trade Representative estimates that trade in goods and services between the US and Canada totalled $872.3 billion in 2025.

Ontario plays a particularly important role in that relationship. In a 2024 fiscal statement based on 2023 trade figures, the Ontario government said the province was the leading export destination for 17 US states and the second-largest destination for another 11 states. Ontario also reported around $500 billion in total trade with the United States that year.

The geography of Lake America makes the dispute especially notable. The lake is shared by the US and Canada, with the international border running through it between Ontario and New York. The Canada Water Agency identifies Lake Ontario as the smallest of the five Great Lakes by surface area, covering 18,960 square kilometres. Reuters reported that about 52 per cent of the lake’s surface area is on the Canadian side.

Trump’s order does not change the border or either country’s legal rights over the water. It also does not alter the long-standing arrangements governing shared waterways. The International Joint Commission says the Boundary Waters Treaty of 1909 was established to help Canada and the US prevent and resolve disputes involving waters shared by the two countries. The executive order focuses on federal naming and contains no provision changing the international boundary, treaty commitments or jurisdiction over the lake.

The lake’s existing name also carries a much older history. The Associated Press traces Ontario to the Huron Indigenous word “oniatarí:io,” meaning “lake of shining waters”, and notes that the name existed before European settlement.

Ontario government sources give slightly different accounts of the precise linguistic origin. The province’s current official history page says Ontario comes from the Iroquois word “kanadario,” meaning “sparkling” water. An earlier Ontario government language resource links it to the Mohawk form “Oniatari’:io,” meaning beautiful lake.

Although the sources differ over the exact language and translation, they agree that the name has Indigenous roots dating back long before the creation of the modern United States and Canada.

The naming dispute also reflects a wider deterioration in relations between the neighbouring countries. The Associated Press reported that Trump has repeatedly suggested that Canada could become the 51st state, a proposal Canadian leaders have rejected. His administration has also relied on tariffs and other trade threats during the dispute.

The proposal to rename the lake first emerged publicly on Tuesday, before Trump signed the executive order two days later.

Canadian officials had already made clear that they would not adopt the new American name. Before Trump signed the order, Canadian Industry Minister Mélanie Joly said, “We’ll always call it Lake Ontario. Period.” Reuters reported that Canadian Prime Minister Mark Carney’s office had not immediately responded to the signed order by Thursday afternoon.

For now, the result is a striking divide: Lake America is the new name for US federal purposes, while Canada continues to officially recognise the same shared body of water as Lake Ontario.

What do you think this Lake America name change says about the current relationship between the US and Canada?