Kevin, although we have never met, I would ask you to seriously consider the advice being offered to you regarding your education.
I am 52 years old, and an engineer for the BNSF. I also have a business degree. My biggest wish, even given the seniority I have, is that I had an advanced degree. Running up and down the mainline, with the goofy "schedules" and hours we work, now makes the likelihood of me being able to obtain one remote at best. In addition to the seniority issues folks have spoken about in this thread, there is the possibility - which, as a railroader, you must consider - of being injured. I'm not trying to spook you or deter you from your goal, but it is a very real and constant possibility. It's possible to sustain an injury as an "event," so to speak, and its also possible that the daily grind of railroading, such as rough joints (couplings), rough track, the constant lateral motion of the locomotive, can produce cumulative damage to you. The time to think about how to cope with the after-effects of a career-ending physical problem or condition is not when it is happening, or after it's happened.
You've probably heard it a million times already, but you are young and have your whole life in front of you. Work the railroad in the summers but please stay in school and earn your degree. Be a full-time rail after you've graduated. The process of obtaining your education will better prepare you for your railroad career, and the possibilities that exist, whether you work in an operating craft or in some other capacity. There's a lot riding on your decision. Whatever you decide, tho, best of luck to you.
