First off, I haven't done it, but as i cruise a lot I get leaflets through about Alaska cruises out of Vancouver. There is usually the option to do the Rocky Mountain tour as well from Calgary. This is usually shown as a 4 day overland tour and I think only 2 days are actually on the train...the other 2 are on a bus (but I could be wrong about that!). However, if it is 4 days total, its a long way to go for 4 days, so perhaps you might want to think about a 7 day Alaska cruise out of Vancouver as well. Most of the cruise lines do them.