What Would It Take to Rename Lake Ontario?
A trade war between the United States and Canada escalated further when President Donald Trump said he is considering renaming Lake Ontario to "Lake America." The remark came as new U.S. tariffs on Canadian goods took effect and talks collapsed. But renaming a Great Lake shared with Canada is not a simple executive decision. It involves legal, procedural, and diplomatic hurdles that make a unilateral name change nearly impossible.
The U.S. has a formal process for naming geographic features. The U.S. Board on Geographic Names (BGN), a federal body created in 1890, sets and maintains uniform name usage across federal agencies. State and local governments, private organizations, or the public can propose name changes. The BGN reviews proposals based on principles of local use, historical significance, and legal authority. For a major natural feature like a Great Lake, an executive order or act of Congress could override the BGN process. President Trump previously used executive action to rename the Gulf of Mexico to the Gulf of America, and mapping services within the U.S. adopted the change. However, that body of water is largely within U.S. jurisdiction under international law. Lake Ontario is different.
Lake Ontario is one of the five Great Lakes and forms part of the international boundary between the U.S. and Canada. Under the Boundary Waters Treaty of 1909, the United States and Canada agreed to jointly manage waters along the border. Neither country can unilaterally alter the name or use of a boundary water without consultation and agreement from the other. The International Joint Commission, established by the treaty, oversees disputes. Any attempt by the U.S. to rename the lake without Canadian consent would violate the spirit, and likely the letter, of the agreement.
Canadian officials have already signaled opposition. They have indicated they would not recognize a new name for the lake, which lies partly in Ontario province. Even if the U.S. federal government decided to rename the lake for domestic purposes, the name would not apply to the Canadian side or to international maps. The United Nations Group of Experts on Geographical Names encourages international standardization, but each country controls names within its territory. For a transboundary feature, both countries must agree. Without that, world maps would show two different names.
The timing of the proposal, amid a heated trade dispute over tariffs on steel, aluminum, and automobiles, suggests a political tactic. The U.S. imposed 50 percent tariffs on $20 billion worth of Canadian products, and Canada plans retaliatory tariffs starting September 8. Threatening to rename a shared natural landmark adds a symbolic dimension to the economic conflict. President Trump has also threatened 50 percent tariffs on all cars, trucks, and automotive parts from Canada starting January 1, 2027, if a deal is not reached.
Why this matters goes beyond trade. The dispute tests the resilience of bilateral institutions that have peacefully managed the border for more than a century. The Boundary Waters Treaty and the International Joint Commission have withstood previous tensions. Unilateral action on a lake name could erode trust and complicate cooperation on shared environmental and water management issues. For now, Lake Ontario remains Lake Ontario on any official map outside the White House.