* Northern End: The Appalachian Mountains continue through the Canadian Maritimes, generally considered to end in Newfoundland. However, some argue the range extends further, including the Avalon Peninsula of Newfoundland.
* Southern End: The southern end of the Appalachians is commonly considered to be in Alabama, near the city of Birmingham. The range gradually diminishes in elevation and becomes less prominent as it reaches the Gulf Coastal Plain.
So, rather than a defined endpoint, the Appalachian Mountains gradually transition into other geographical features.
It's worth noting that the Appalachian Trail, a famous hiking trail, officially ends at Springer Mountain in Georgia, but the Appalachian Mountains themselves extend further south.