Uarl mountains and the Uarl rivers
The Sulu Sea helps form the western boundary of the Philippines.
Ural Mountains and Ural River
The Ural Mountains form the western boundary for the continent of Asia.
Two rivers partially form Illinois State's Eastern boundary. The Wabash River is one river that forms Illinois' boundary. The Ohio River is the other river that forms the state's boundary.
It is the Danube River.
western
The Missouri River and its tributary, the Big Sioux, form the western border of Iowa.
The Andes Mountains form Chile's natural eastern boundary, while the Pacific Ocean acts as its natural western boundary.
No, they formed the eastern boundary, in the form of the continental divide.
appalachians
The Mississippi River forms the western boundary of Illinois.