What mountains cut through the western part of the northeast?

The Appalachian Mountains cut through the western part of the northeast region of the United States. This mountain range extends from the Canadian province of Newfoundland and Labrador in the north to central Alabama in the southern United States. The Appalachian Mountains are a system of parallel ridges, valleys, and plateaus that are geologically old and eroded compared to the younger Rocky Mountains in the western United States.