The Rocky Mountains are tall and more pointed compared to the Appalachian Mountains which are smaller and have duller points. This shows that the Appalachian Mountains have had more time to erode while the Rocky Mountains have not.
You must be thinking of the Rocky Mountains.
Extrusive igneous rock found in the southern half of the Rocky Mountains indicates that this is section of mountains was once VOLCANIC!
Rocky mountains
the rocky mountains
As mountains go, they are relatively new, and have not weathered.
The Rocky Mountains and the Appalachian Mountains.
Missouri river
The Great Plains.
Europes Ural mtns or The U.S's rocky mountains
The Great Plains is the huge expanse of flatlands from the Rocky Mountains eastward to the Mississippi River.
The Rocky Mountains
The Rocky Mountains are in Canada.We will climb the rocky mountains this week.