Trump orders U.S. maps to call Lake Ontario ‘Lake America’

President Donald Trump signed an executive order on 27 August directing the Interior Department to rename Lake Ontario as Lake America in every U.S. federal map, contract and database. He told reporters in the Oval Office that the change was “effective immediately.” The written order gives Interior Secretary Doug Burgum and the Board on Geographic Names 30 days to update the Geographic Names Information System and to strip official U.S. references to the old name “consistent with applicable law.”

The order does not bind Canada, New York State, the International Joint Commission or commercial mapmakers. About 52 percent of the lake’s surface sits on the Canadian side. The remainder lies in New York. Prime Minister Mark Carney answered the same afternoon. “The name Lake Ontario comes from the Wendat word Ontari’io, which, appropriately, means ‘the lake is beautiful, the lake is big,’” he wrote. He noted that the name is more than 400 years old and predates both Canadian Confederation and the U.S. Declaration of Independence. “Canadians also know that naming reality means calling it Lake Ontario. Then, now and always.”

New York Governor Kathy Hochul was shorter: “New York won’t be calling it that.” Ontario Premier Doug Ford wrote that it remains Lake Ontario “to Canadians and the rest of the world. Now and forever.”

A trade fight with a new label

The renaming sits inside a collapsed trade negotiation. After talks broke down last week, Washington imposed 50 percent tariffs on about $20 billion of Canadian goods. Ottawa answered with tariffs of 15 to 50 percent on selected U.S. exports. Trump had previewed the lake change on social media earlier in the week, posting a map with “Lake Ontario” crossed out and writing that the United States did not expect to do “much business with Ontario any longer.”

In the Oval Office he stood in front of a large Great Lakes map titled “Making the Great Lakes Even Greater,” with “Lake America” printed over the easternmost lake. He compared the step to last year’s federal decision to call the Gulf of Mexico the Gulf of America in U.S. usage. Asked about other lakes, he joked that he might change more than one.

The text of the order argues that the United States is “the greatest protector of the Great Lakes” and that the water body “will continue to play a [central] role in shaping America’s future and the global economy.” Federal agencies must now use the new name on maps, procurement papers and internal documents. Shipping charts used by the U.S. Coast Guard and the National Oceanic and Atmospheric Administration will have to be revised. Canadian charts will not.

What the name actually covers

Lake Ontario is the smallest of the five Great Lakes by surface area, about 18,960 square kilometres, and the last lake in the chain before the St. Lawrence River. It takes water from the Niagara River and the Welland Canal and sends it east toward the Atlantic. Cities on its shores include Toronto, Hamilton, Rochester and Kingston. The name Ontario itself was later applied to the Canadian province that occupies the north shore.

Wendat speakers used a form of Ontari’io for the lake long before English or French surveyors arrived. French maps of the seventeenth century already carry variants of the name. British and later American charts kept it. No previous U.S. administration has attempted a unilateral federal rename of a shared Great Lake.

Practical effects will show up first in U.S. government documents. A federal environmental impact statement written after the 30-day clock runs out will say Lake America. A Canadian assessment of the same shoreline will still say Lake Ontario. Insurance policies, port tariffs and binational water-quality reports that cite both governments will have to carry two names for one body of water.

Who has to follow the order

Burgum’s department controls the Geographic Names Information System, the official U.S. gazetteer. Once that database changes, other federal systems that pull from it will follow. State governments are not obliged to copy the federal list. Hochul’s refusal means New York highway signs, school textbooks bought by the state and the Department of Environmental Conservation can keep the historic name.

International hydrographic practice runs through the International Hydrographic Organization and through long-standing U.S.–Canada arrangements on the Great Lakes. Those bodies have not been asked to vote. Commercial publishers, from school-atlas houses to navigation-app companies, will decide on their own whether a U.S. federal label is enough to change a name that appears on every Canadian product.

The episode now sits beside the tariff lists as a public marker of how far the two governments have moved from the language of a shared continental water system. Carney’s reply treated the rename as one more item in a list that already included trade policy, foreign policy and national monuments. Ford and Hochul treated it as a naming error that their jurisdictions would simply ignore.

For ship captains and hydrologists the lake has not moved. For U.S. federal clerks, the file name has. The next test is whether Burgum’s 30-day rewrite produces a clean gazetteer entry or a split record that map users will have to decode by country.