For the White Pass railroad, I find it odd that on their website some of the dates are updated and some are not. We're looking at doing the Journey on the White Pass Railroad trip, which is their shorter 2hr, $99/person tour, but the dates aren't available yet. But when I look at the White Pass Summit Excursion (the 2.5hr, $134/person tour), it doesn't look like it's available the day we are in port (May 26th - sailing with RCI). Hopefully they continue to update their website with more dates!
Edit: Actually looks like it is available when we get in! Turns out you can toggle between the time you want to depart, and from their the calendar updates with what days are available. For example, on May 27th there is a 9am, 1pm, and 2pm train.