The Appalachian Mountains (i/ˌæpəˈleɪʃᵻn/ or /ˌæpəˈlætʃᵻn/,[note 1] French: les Appalaches), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period and once reached elevations similar to those of the Alps and the Rocky Mountains before they were eroded. The Appalachian chain is a barrier to east-west travel as it forms a series of alternating ridgelines and valleys oriented in opposition to any road running east-west. COUNT 4
QSN1 What are the Appalachian mountains called in French? ANS1 les Appalaches QSN2 What are the Appalachian mountains? ANS2 a system of mountains in eastern North America QSN3 When did the Appalachian mountains form? ANS3 roughly 480 million years ago QSN4 In what era did the mountains form? ANS4 Ordovician Period