How tall were the appalachian moutains?

[Second]

If I remember correctly, the appalachian mountains are older then the rocky’s, and that’s why they are not as tall, erosion ect. But how tall were all those millennia ago?

[Pucky_Schumer]

The Appalachians are much lower than many other ranges because they are much, much older, hence much more eroded. According to this site:

"… they are worn-away remnants of a once-high alpine plateau-- worn away like the teeth of an old horse by the elements of wind, rain, and ice over the past 200 million years.

What are today the coalfields of southern West Virginia were once a high plateau rising to heights of as much as 10,000 to 18,000 feet above sea level. This odd, Tibetan landscape was flanked on the south and east by the even higher Alleghenian Mountain range, which likely exceeded the Himalaya’s in height.

[Yossarian]

Applying the principle of Uniformitarianism, we assume that the ancient Appalachia were similar to modern-day mountain ranges that form at continental convergent boundaries, such as the Himalayas or Alps.

[AHunter3]

The even older Ouachita mountain range that apparently ran east-west around the latitude of Oklahoma must have been impressive in their days too.

[Yossarian]

More impressive are the same Ouachitas that sweep southwestward through Texas, passing under Dallas and popping up briefly in Central Texas (Llano) and West Texas (Marathon Basin): part of a once Himalayan-scale range not only worn down, but buried in the subsurface.

And then there are the Precambrain mountain ranges…

[AHunter3]

OK, so I was off to the north a bit. Yeah, those mountains.

[Yossarian]

No, you were right. The Ouachitas crop out at the surface in Oklahoma and Arkansas–I was just commenting on the subsurface Ouachitas as the ultimate example of mountains that used to be higher!