The Appalachian Mountains were once as tall as the Himalayas.

The Appalachians were a part of the same tectonic processes that created the Himalayas and other significant mountain ranges around 300 million years ago. The Appalachians rose to heights similar to those of the Himalayas at that period. But the Appalachians have since lost height as a result of massive erosion over millions of years, giving rise to the more muted peaks and undulating hills that now define the range. The powerful geological forces that have molded the Earth's terrain are demonstrated by the Appalachians' ancient majesty.