This regional view shows the striking visual effect of the valley-and-ridge topography of the Appalachian Mountains as viewed from the International Space Station. The image shows more than 500 kilometers (300 miles) of this low mountain chain from northeast Pennsylvania (top right) to southern West Virginia, where a dusting of snow covers a patch of land (lower left). The Appalachian Mountains appear striped because the ridges are forested, providing a dense and dark canopy cover, while the valleys are farmed with crops that generally appear as lighter-toned areas.