Q: We would like to travel from Anchorage to Fairbanks by rail. Do folks typically ride the railway both ways or fly back from Fairbanks to Anchorage?
A: The Alaska Railroad  departs once a day for Fairbanks. It is about a 12 hour ride one way. You would need to stay in Fairbanks and return the next day to do roundtrip on the railroad. Your return would depend on how much time you want to spend traveling. If you are short on time I would recommend taking the train one way and flying back to Anchorage the other. If you take Alaska Airlines the return flight would be less than an hour.
If you have more time, I would recommend touring Fairbanks  one day, then taking the rail to Denali the next day. Spend two nights in Denali with one full day touring Denali National Park  and then return to Anchorage by bus .