CSX K201-21, empty phosphate bound for Mulberry, Florida, blasts at track speed over the hogbacks that frequent this part of Georgia. The Fitzgerald Sub of CSX is one of the most varied lines as far as profile goes, in my opinion. The line starts in the foothills of the Appalachian Mountains and terminates in the Okefenokee Swamp. In between both locations there are hundreds of grade changes, several major river crossings, and lots of trains.