A natural boundary is a natural feature such as a river or mountain range that divides an area into sections.
Mississippi river
Some examples of artificial boundaries are state borders that do not follow a river or other natural feature, such as the boundary between Oregon and California. Most city and county boundaries are also artificial.
Jamaica is a self contained island - it has no land boundaries.
Mississippi River & . . .
The Amazon The Aconcagua The Bio Bio are 3 examples, there are many many more.
Which river form the boundaries of the Great Lakes states
YES
Utah
the Mississippi river
columbia river
From the Atlantic Ocean to the Mississippi River