WASHINGTON — President Donald Trump signed an order Thursday renaming Lake Ontario as “Lake America” for U.S. federal use. Canada, New York and private mapping companies do not have to follow it.

Canadian Prime Minister Mark Carney quickly rejected the change. He said Canadians will continue calling the shared body of water Lake Ontario.

The order arrives as relations between the longtime allies deteriorate. Trade negotiations collapsed last week, and both countries have imposed tariffs on billions of dollars in cross-border goods.

Lake America Order Changes Federal Maps

The executive order directs the interior secretary to complete the name change within 30 days. The secretary must work with the U.S. Board on Geographic Names to update the Geographic Names Information System.

Federal departments and agencies will then use “Lake America” on maps, contracts, records and official communications. The order also calls for removing references to Lake Ontario from the federal database.

Trump told reporters the change would take effect immediately. He said he had considered the new name for a long time.

The White House presented the change as recognition of the lake’s importance to U.S. commerce, energy and national security. The order says the United States supplies nine of the 11 icebreaking vessels operating on the Great Lakes.

It also claims that the United States invested nearly $4 billion in protecting the Great Lakes ecosystem over the past decade. The administration did not provide a detailed comparison of Canadian spending.

Federal Authority Has Clear Limits

The president can direct federal agencies to adopt a geographic name. That power does not allow him to control what Canada, international organizations or private companies call the lake.

The U.S. Geological Survey says decisions from the Board on Geographic Names bind federal departments and agencies. States may maintain separate naming databases and policies.

Private mapping companies such as Google, Apple and Esri often use federal geographic data. However, they are not required to adopt names selected by the federal board.

New York can also continue using Lake Ontario on state maps and documents. Gov. Kathy Hochul made her position clear Thursday.

“New York won’t be calling it that,” Hochul wrote on social media.

Canada controls approximately 52% of the lake’s surface area. The remaining portion lies within New York.

Trump’s order argues that the deepest sections sit in U.S. territory. The administration therefore claims the United States holds most of the lake’s water by volume.

Canada Defends Lake Ontario Name

Carney said the Lake Ontario name predates both Canadian Confederation and the United States’ Declaration of Independence.

“Canadians also know that naming reality means calling it Lake Ontario, then, now and always,” Carney said, according to Reuters.

The name first appeared in written records more than 400 years ago. A Canadian government history traces Ontario to an Iroquoian term meaning “vast body of water.” Other translations include “sparkling water” or “beautiful lake.”

Grand Chief Pierre Picard of the Wendat Nation condemned Trump’s decision. He accused the president of trying to erase Indigenous history from the landmark’s name.

The province of Ontario later took its name from the lake. Ontario officially became a Canadian province in 1867.

Lake Connects Millions Across the Border

Lake Ontario is the smallest Great Lake by surface area, but it remains a major economic and environmental resource. Water flows from the lake into the St. Lawrence River before reaching the Atlantic Ocean.

The lake covers about 7,340 square miles, according to the National Oceanic and Atmospheric Administration. Approximately 5.6 million people live near its shores, divided almost evenly between the United States and Canada.

Communities on both sides rely on the lake for drinking water, shipping, fishing, recreation and electricity generation. Ports along the lake connect the Great Lakes system to international trade routes.

The United States and Canada also share responsibility for water quality, shipping and environmental protection. A federal name change does not alter those agreements or the international boundary running through the lake.

Name Change Deepens Trade Dispute

Trump first threatened to rename the lake after trade negotiations with Canada broke down. He accused Canada of mistreating the United States through tariffs and other trade policies.

USA Herald previously reported that Canada plans dollar-for-dollar retaliatory tariffs beginning Sept. 8. The response follows new 50% U.S. tariffs affecting about $20 billion in Canadian goods.

The latest dispute includes dairy products, vehicles, steel, wine, furniture and agricultural equipment. Both governments blame the other for the failure to reach a new agreement.

Trump made the connection between the trade dispute and the lake’s name explicit when he first proposed the change Tuesday. During Thursday’s signing ceremony, he also suggested that the Atlantic or Pacific oceans could be renamed.

The administration previously used the same federal process to change the Gulf of Mexico to the Gulf of America. Federal geographic records adopted that name within weeks, although Mexico and many international organizations retained the traditional name.

“Lake America” will likely appear on federal maps and government documents soon. Beyond Washington, Lake Ontario will remain in use across Canada, New York and any private organization that declines to follow the administration’s decision.