Donald Trump has signed an executive order telling Interior Secretary Doug Burgum to scrub every federal reference to Lake Ontario and replace it with Lake America. Thirty days is the window Burgum and the U.S. Board on Geographic Names have to finish the job, and some of it is already done. The Geographic Names Information System reflects the new name. So do Google Maps and Apple Maps, though holdouts remain among other mapping providers.

The order landed a day after trade talks between Washington and Ottawa fell apart. The U.S. Slapped 50 percent tariffs on roughly $20 billion of Canadian goods, and Canada answered with its own dollar-for-dollar tariffs. Standing next to a map labelled 'Making the Great Lakes Even Greater' in the Oval Office, Trump told reporters he'd been thinking about the rename for a long time, and floated the idea that other bodies of water could get the same treatment. He also called Canadian officials 'nasty people' who had 'treated us very badly,' per ABC News.

Burgum's line on X: the waters bordering America should reflect its greatness.

What this actually costs is where things get murky. Linda Bilmes, a Harvard Kennedy School lecturer and former Commerce Department CFO, told Newsweek that renaming projects are never as simple as they look on paper. Printed maps, brochures, road signage, park plaques, trail markers, all of it needs replacing, and that's before you count the labour hours.

Oswego's Republican mayor, Robert Corradino, put a number on it for his own city of 17,000: several thousand dollars at minimum, money he says the town can't spare while it's trying to hold the line on taxes. He's against the whole idea. New York State, the only U.S. State that actually touches the lake, has said it has no plans to adopt the new name at all.

There's precedent for how big these bills can get. When the Congressional Budget Office looked at codifying the Gulf of America rename, it landed on a figure up to $500,000 over five years just for federal documents and maps. The Department of War rebrand was a different order of magnitude entirely, with CBO estimates ranging from $10 million for a modest rollout to $125 million for a fast, broad one, and potentially hundreds of millions if Congress made it law.

Canada isn't playing along, and it can't be forced to. Prime Minister Mark Carney posted that Ontario comes from the Wendat word Ontari'io, meaning the lake is beautiful, the lake is big, and that the name predates both Confederation and American independence. 'Naming reality means calling it Lake Ontario,' he wrote, 'then, now and always.' Ontario Premier Doug Ford said much the same thing.

Washington's writ stops at the border. What happens to the paperwork on this side of it is still being worked out.