The Black Sea form most of the northern borders of Turkey.
Kentucky forms most of the northern border of Tennessee.
MONGOLIA makes up most of China's northern border.
The country that forms most of the northern border of the United States is Canada. The country directly to the south is Mexico.
The country that forms most of the northern border of the United States is Canada. The country directly to the south is Mexico.
Rio Grande forms the Southern border of the United states.
Canada
Canada
Canada
ALBORZ
Himalayas
Elburz Mountains
The largest country in the world: Canada