The Rocky Mountains
Since parts of the east and west coasts of the US are roughly parallel, something parallel to one of them would be parallel to the other. The Appalachians are closer to the east coast than the west.
The name of the mountain range on the west coast of the US is the Sierra Nevada.
The Sierra Nevada Mountain range and Cascade mountains
The Rocky Mountains
The Appalachian Mountain Range runs parallel to the east coast of the US, stretching from northern Alabama to Maine. It is one of the oldest mountain ranges in North America.
Coastal Range
The Appalachian mountains are closer to the east coast of the US. They run parallel to the coast and are located mainly in the eastern United States.
Key West Florida
The Appalachian Mountains run along the eastern coast of the US and parallel to the Atlantic Ocean, stretching from Alabama to Canada. This mountain range is known for its diverse ecosystems and is a popular destination for outdoor activities such as hiking and camping.
The Rocky Mountains
The Appalachian Mountains run fairly parallel to the East Coast of the US. The Rockies run down the West Coast.
The Pacific Ocean is on the west coast of the US.