caucausus mountains
A physical feature that forms part of the border of New York State is Lake Ontario. If you mean the border around New York City, a physical feature would be the Hudson River.
The Mississippi River forms Arkansas' eastern border.
The physical feature that forms Uruguay's western boundary with Argentina is the Uruguay River. It also forms part of the Brazilian-Argentine border.
Mexico
The Mississippi river
The Rio Grande river, also known as Rio Bravo in Mexico.
A River
The Ural Mountains
Mississippi river
The Ural Mountains
The Ural Mountains
The amur river