Eastern U.S.A.
The Atlantic ocean.
Spain forms the eastern boundary of Portugal.
The southern half of the eastern boundary of Alabama is the Chattahoochee River.
A divergent boundary.
they were the Oregon and spanish
The Indian Ocean forms the eastern boundary of Africa.
Russia does not share an eastern border with anyone, but it is on the coast of the Bering Sea and just across that is the US state of Alaska.
The country is Eritrea, and it's eastern boundary is formed by the Red Sea.
The Atlantic Ocean.
Spain is the only country to border Portugal to the east.
The Mississippi River is the East boundary for Arkansas.