My opinion only, but 4 days is not enough time on a cruise tour- land portion. A lot of your time will be in transit compared to actual time at the destination. There is only 2 "stop overs", if going by rail, between Anchorage and Fairbanks- Talkeetna and Denali Park. Be aware that the total time is 12 hours. Denali Park is a highpoint for most. If wildlife is a priority you need at least the Tundra Wilderness tour, but a better value is the NPS Shuttle buses, with my min. recommended distance in Eielson mile 66. The tour bus goes to mile 53 unless McKinley is viewable (rare). Plenty of ranger activities too. Tours in Fairbanks include a boat ride and gold dredge tour, Anchorage - usually the Native History museum. Frankly there is so much more to both cities. If going with Princess- they sometimes include a night at the McKinley princess- be aware this is out in the middle of nowhere, nearest town is Talkeetna 40 miles away (great options for McKinley flights) and the National Park entrance of Denali is 100 miles. Consider going for 7 days interior- you will see and do much more. Or consider going on your own. Very very simple to do and you can concentrate on your interests, plus see all the "small stuff" in between. You can use the "tours" as a guide. Only one road/rail. Alaska RR also offers packages and the Toursaver has a 2 for 1 coupon- look at all options.