Geologic image in the Kentucky Geological Survey data repository.Image Name: Roadbed Support, Letcher County Image Date: 10/3/2007 Category: photo_scene Source: Carey, Dan Format: JPG Size (MB): 0.8 Pixel Dimensions: 1624 x 1596 Description: Additional support is commonly needed to prevent pavement failure for highways constructed on shale, like this in the Pikeville Formation in Letcher County. Photo by Dan Carey, Kentucky Geological Survey.