the appalachians are a blank that runs from southern canada to central alabama
The Appalachian Mountains (/ ˌæpəˈlæʃɪn,-ˈleɪtʃɪn / (listen), 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. They once reached elevations similar to those of the Alps and the Rocky Mountains before naturally occurring erosion. The Appalachian chain is a barrier to east-west travel, as it forms a series of alternating ridgelines and valleys oriented in opposition to most roads running east or west.