A westbound Union Pacific coal empty curves through “Little 10 Curve” at the west end of Rocky, Colorado, on the morning on June 2, 2013. The train will be on the foreground track momentarily when it enters Big 10 Curve. From left to right in the background is Eisele (formerly Clay) siding, the mouth of Coal Creek Canyon, the ridge that Tunnel 1 cuts through and the Flatiron rock formations where the main line borrows through Tunnel’s 2 to 8.